Introduce special IrDeclarationOrigin's for for-loop variables

FOR_LOOP_ITERATOR
 - temporary variable for for-loop iterator

FOR_LOOP_VARIABLE
 - `x` in `for (x in xs)`

FOR_LOOP_IMPLICIT_VARIABLE
 - temporary variable for for-loop with destructuring, e.g.:
   for ((x, y) in xys)
   =>
   for (tmp in xys) {
     val (x, y) = tmp
   }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/LoopExpressionGenerator.kt

@@ -155,7 +155,7 @@ class LoopExpressionGenerator(statementGenerator: StatementGenerator) : Statemen
 
         val iteratorCall = statementGenerator.pregenerateCall(iteratorResolvedCall)
         val irIteratorCall = callGenerator.generateCall(ktLoopRange, iteratorCall, IrStatementOrigin.FOR_LOOP_ITERATOR)
-        val irIterator = scope.createTemporaryVariable(irIteratorCall, "iterator")
+        val irIterator = scope.createTemporaryVariable(irIteratorCall, "iterator", origin = IrDeclarationOrigin.FOR_LOOP_ITERATOR)
         val iteratorValue = VariableLValue(irIterator)
         irForBlock.statements.add(irIterator)
 
@@ -178,12 +178,12 @@ class LoopExpressionGenerator(statementGenerator: StatementGenerator) : Statemen
         val irLoopParameter =
                 if (ktLoopParameter != null && ktLoopDestructuringDeclaration == null)
                     context.symbolTable.declareVariable(
-                            ktLoopParameter.startOffset, ktLoopParameter.endOffset, IrDeclarationOrigin.DEFINED,
+                            ktLoopParameter.startOffset, ktLoopParameter.endOffset, IrDeclarationOrigin.FOR_LOOP_VARIABLE,
                             getOrFail(BindingContext.VALUE_PARAMETER, ktLoopParameter),
                             irNextCall
                     )
                 else
-                    scope.createTemporaryVariable(irNextCall, "loop_parameter")
+                    scope.createTemporaryVariable(irNextCall, "loop_parameter", origin = IrDeclarationOrigin.FOR_LOOP_IMPLICIT_VARIABLE)
         irInnerBody.statements.add(irLoopParameter)
 
         if (ktLoopDestructuringDeclaration != null) {

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/builders/Scope.kt

@@ -50,9 +50,14 @@ class Scope(val scopeOwnerSymbol: IrSymbol) {
         return if (nameHint != null) "tmp${index}_$nameHint" else "tmp$index"
     }
 
-    fun createTemporaryVariable(irExpression: IrExpression, nameHint: String? = null, isMutable: Boolean = false): IrVariable =
+    fun createTemporaryVariable(
+            irExpression: IrExpression,
+            nameHint: String? = null,
+            isMutable: Boolean = false,
+            origin: IrDeclarationOrigin = IrDeclarationOrigin.IR_TEMPORARY_VARIABLE
+    ): IrVariable =
             IrVariableImpl(
-                    irExpression.startOffset, irExpression.endOffset, IrDeclarationOrigin.IR_TEMPORARY_VARIABLE,
+                    irExpression.startOffset, irExpression.endOffset, origin,
                     createDescriptorForTemporaryVariable(irExpression.type, nameHint, isMutable),
                     irExpression
             )

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrDeclarationOrigin.kt

@@ -19,6 +19,9 @@ package org.jetbrains.kotlin.ir.declarations
 interface IrDeclarationOrigin {
     object DEFINED : IrDeclarationOriginImpl("DEFINED")
     object FAKE_OVERRIDE : IrDeclarationOriginImpl("FAKE_OVERRIDE")
+    object FOR_LOOP_ITERATOR : IrDeclarationOriginImpl("FOR_LOOP_ITERATOR")
+    object FOR_LOOP_VARIABLE : IrDeclarationOriginImpl("FOR_LOOP_VARIABLE")
+    object FOR_LOOP_IMPLICIT_VARIABLE : IrDeclarationOriginImpl("FOR_LOOP_IMPLICIT_VARIABLE")
     object PROPERTY_BACKING_FIELD : IrDeclarationOriginImpl("PROPERTY_BACKING_FIELD")
     object DEFAULT_PROPERTY_ACCESSOR : IrDeclarationOriginImpl("DEFAULT_PROPERTY_ACCESSOR")
     object DELEGATE : IrDeclarationOriginImpl("DELEGATE")

compiler/testData/ir/irCfg/loop/factorial.txt

@@ -9,7 +9,7 @@ CONTENT
       5 GET_VAR 'value-parameter i: Int' type=kotlin.Int origin=null
       6 CALL 'rangeTo(Int): IntRange' type=kotlin.ranges.IntRange origin=RANGE
       7 CALL 'iterator(): IntIterator' type=kotlin.collections.IntIterator origin=FOR_LOOP_ITERATOR
-      8 VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.IntIterator
+      8 VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.IntIterator
       9 WHILE label=null origin=FOR_LOOP_INNER_WHILE
 OUTGOING -> BB 1
     While entry: WHILE label=null origin=FOR_LOOP_INNER_WHILE
@@ -26,7 +26,7 @@ INCOMING <- BB 1
 CONTENT
       1 GET_VAR 'tmp0_iterator: IntIterator' type=kotlin.collections.IntIterator origin=null
       2 CALL 'next(): Int' type=kotlin.Int origin=FOR_LOOP_NEXT
-      3 VAR val j: kotlin.Int
+      3 VAR FOR_LOOP_VARIABLE val j: kotlin.Int
       4 SET_VAR 'result: Int' type=kotlin.Unit origin=MULTEQ
 OUTGOING -> BB 1
     While entry: WHILE label=null origin=FOR_LOOP_INNER_WHILE

compiler/testData/ir/irCfg/loop/isPerfect.txt

@@ -11,7 +11,7 @@ CONTENT
       7 CALL 'div(Int): Int' type=kotlin.Int origin=DIV
       8 CALL 'rangeTo(Int): IntRange' type=kotlin.ranges.IntRange origin=RANGE
       9 CALL 'iterator(): IntIterator' type=kotlin.collections.IntIterator origin=FOR_LOOP_ITERATOR
-     10 VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.IntIterator
+     10 VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.IntIterator
      11 WHILE label=null origin=FOR_LOOP_INNER_WHILE
 OUTGOING -> BB 1
     While entry: WHILE label=null origin=FOR_LOOP_INNER_WHILE
@@ -28,7 +28,7 @@ INCOMING <- BB 1
 CONTENT
       1 GET_VAR 'tmp0_iterator: IntIterator' type=kotlin.collections.IntIterator origin=null
       2 CALL 'next(): Int' type=kotlin.Int origin=FOR_LOOP_NEXT
-      3 VAR val m: kotlin.Int
+      3 VAR FOR_LOOP_VARIABLE val m: kotlin.Int
       4 WHEN type=kotlin.Unit origin=null
       5 GET_VAR 'value-parameter n: Int' type=kotlin.Int origin=null
       6 GET_VAR 'm: Int' type=kotlin.Int origin=null

compiler/testData/ir/irText/expressions/breakContinueInLoopHeader.txt

@@ -44,7 +44,7 @@ FILE /breakContinueInLoopHeader.kt
         condition: CONST Boolean type=kotlin.Boolean value='true'
         body: BLOCK type=kotlin.Unit origin=null
           BLOCK type=kotlin.Unit origin=FOR_LOOP
-            VAR IR_TEMPORARY_VARIABLE val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
+            VAR FOR_LOOP_ITERATOR val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
               CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
                 $this: BLOCK type=kotlin.collections.List<kotlin.String> origin=ELVIS
                   VAR IR_TEMPORARY_VARIABLE val tmp0_elvis_lhs: kotlin.collections.List<kotlin.String>?
@@ -62,7 +62,7 @@ FILE /breakContinueInLoopHeader.kt
               condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
                 $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
               body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-                VAR val s: kotlin.String
+                VAR FOR_LOOP_VARIABLE val s: kotlin.String
                   CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                     $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
   FUN public fun test4(ss: kotlin.collections.List<kotlin.String>?): kotlin.Unit
@@ -72,7 +72,7 @@ FILE /breakContinueInLoopHeader.kt
         condition: CONST Boolean type=kotlin.Boolean value='true'
         body: BLOCK type=kotlin.Unit origin=null
           BLOCK type=kotlin.Unit origin=FOR_LOOP
-            VAR IR_TEMPORARY_VARIABLE val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
+            VAR FOR_LOOP_ITERATOR val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
               CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
                 $this: BLOCK type=kotlin.collections.List<kotlin.String> origin=ELVIS
                   VAR IR_TEMPORARY_VARIABLE val tmp0_elvis_lhs: kotlin.collections.List<kotlin.String>?
@@ -90,7 +90,7 @@ FILE /breakContinueInLoopHeader.kt
               condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
                 $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
               body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-                VAR val s: kotlin.String
+                VAR FOR_LOOP_VARIABLE val s: kotlin.String
                   CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                     $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
   FUN public fun test5(): kotlin.Unit

compiler/testData/ir/irText/expressions/for.txt

@@ -3,28 +3,28 @@ FILE /for.kt
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
   FUN public fun testIterable(ss: kotlin.collections.List<kotlin.String>): kotlin.Unit
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
             BLOCK type=kotlin.Unit origin=null
@@ -34,14 +34,14 @@ FILE /for.kt
     VALUE_PARAMETER value-parameter pp: kotlin.collections.List<kotlin.Pair<kotlin.Int, kotlin.String>>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.Pair<kotlin.Int, kotlin.String>>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.Pair<kotlin.Int, kotlin.String>>
           CALL 'iterator(): Iterator<Pair<Int, String>>' type=kotlin.collections.Iterator<kotlin.Pair<kotlin.Int, kotlin.String>> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter pp: List<Pair<Int, String>>' type=kotlin.collections.List<kotlin.Pair<kotlin.Int, kotlin.String>> origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<Pair<Int, String>>' type=kotlin.collections.Iterator<kotlin.Pair<kotlin.Int, kotlin.String>> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR IR_TEMPORARY_VARIABLE val tmp1_loop_parameter: kotlin.Pair<kotlin.Int, kotlin.String>
+            VAR FOR_LOOP_IMPLICIT_VARIABLE val tmp1_loop_parameter: kotlin.Pair<kotlin.Int, kotlin.String>
               CALL 'next(): Pair<Int, String>' type=kotlin.Pair<kotlin.Int, kotlin.String> origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<Pair<Int, String>>' type=kotlin.collections.Iterator<kotlin.Pair<kotlin.Int, kotlin.String>> origin=null
             VAR val i: kotlin.Int

compiler/testData/ir/irText/expressions/forWithBreakContinue.txt

@@ -3,14 +3,14 @@ FILE /forWithBreakContinue.kt
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
             BLOCK type=kotlin.Nothing origin=null
@@ -19,26 +19,26 @@ FILE /forWithBreakContinue.kt
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=OUTER origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s1: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s1: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
             BLOCK type=kotlin.Nothing origin=null
               BLOCK type=kotlin.Unit origin=FOR_LOOP
-                VAR IR_TEMPORARY_VARIABLE val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
+                VAR FOR_LOOP_ITERATOR val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
                   CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
                     $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
                 WHILE label=INNER origin=FOR_LOOP_INNER_WHILE
                   condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
                     $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
                   body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-                    VAR val s2: kotlin.String
+                    VAR FOR_LOOP_VARIABLE val s2: kotlin.String
                       CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                         $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
                     BLOCK type=kotlin.Nothing origin=null
@@ -50,14 +50,14 @@ FILE /forWithBreakContinue.kt
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=null origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
             BLOCK type=kotlin.Nothing origin=null
@@ -66,26 +66,26 @@ FILE /forWithBreakContinue.kt
     VALUE_PARAMETER value-parameter ss: kotlin.collections.List<kotlin.String>
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: kotlin.collections.Iterator<kotlin.String>
           CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
         WHILE label=OUTER origin=FOR_LOOP_INNER_WHILE
           condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
             $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val s1: kotlin.String
+            VAR FOR_LOOP_VARIABLE val s1: kotlin.String
               CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'tmp0_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
             BLOCK type=kotlin.Nothing origin=null
               BLOCK type=kotlin.Unit origin=FOR_LOOP
-                VAR IR_TEMPORARY_VARIABLE val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
+                VAR FOR_LOOP_ITERATOR val tmp1_iterator: kotlin.collections.Iterator<kotlin.String>
                   CALL 'iterator(): Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=FOR_LOOP_ITERATOR
                     $this: GET_VAR 'value-parameter ss: List<String>' type=kotlin.collections.List<kotlin.String> origin=null
                 WHILE label=INNER origin=FOR_LOOP_INNER_WHILE
                   condition: CALL 'hasNext(): Boolean' type=kotlin.Boolean origin=FOR_LOOP_HAS_NEXT
                     $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
                   body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-                    VAR val s2: kotlin.String
+                    VAR FOR_LOOP_VARIABLE val s2: kotlin.String
                       CALL 'next(): String' type=kotlin.String origin=FOR_LOOP_NEXT
                         $this: GET_VAR 'tmp1_iterator: Iterator<String>' type=kotlin.collections.Iterator<kotlin.String> origin=null
                     BLOCK type=kotlin.Nothing origin=null

compiler/testData/ir/irText/expressions/forWithImplicitReceivers.txt

@@ -90,7 +90,7 @@ FILE /forWithImplicitReceivers.kt
     $receiver: VALUE_PARAMETER this@test: IReceiver
     BLOCK_BODY
       BLOCK type=kotlin.Unit origin=FOR_LOOP
-        VAR IR_TEMPORARY_VARIABLE val tmp0_iterator: IntCell
+        VAR FOR_LOOP_ITERATOR val tmp0_iterator: IntCell
           CALL 'iterator() on FiveTimes: IntCell' type=IntCell origin=FOR_LOOP_ITERATOR
             $this: GET_VAR 'this@test: IReceiver' type=IReceiver origin=null
             $receiver: GET_OBJECT 'FiveTimes' type=FiveTimes
@@ -99,7 +99,7 @@ FILE /forWithImplicitReceivers.kt
             $this: GET_VAR 'this@test: IReceiver' type=IReceiver origin=null
             $receiver: GET_VAR 'tmp0_iterator: IntCell' type=IntCell origin=null
           body: BLOCK type=kotlin.Unit origin=FOR_LOOP_INNER_WHILE
-            VAR val i: kotlin.Int
+            VAR FOR_LOOP_VARIABLE val i: kotlin.Int
               CALL 'next() on IntCell: Int' type=kotlin.Int origin=FOR_LOOP_NEXT
                 $this: GET_VAR 'this@test: IReceiver' type=IReceiver origin=null
                 $receiver: GET_VAR 'tmp0_iterator: IntCell' type=IntCell origin=null