Set correct IR origins for inc/dec operations

NB: in order to produce correct IR origins, the source element kinds for
some FIR elements has been changed. As a side effect, mapping PSI to FIR
slightly changed: namely, for `a[b]++`, `a[b]` used to be mapped on
`set` call or callable reference, but now it is mapped on `get` call.

^KT-61891: Fixed
^KT-64387: Fixed

compiler/testData/ir/irText/regressions/coercionInLoop.fir.ir.txt

@@ -1,38 +0,0 @@
-FILE fqName:<root> fileName:/coercionInLoop.kt
-  FUN name:box visibility:public modality:FINAL <> () returnType:kotlin.String
-    BLOCK_BODY
-      VAR name:a type:kotlin.DoubleArray [val]
-        CONSTRUCTOR_CALL 'public constructor <init> (size: kotlin.Int) declared in kotlin.DoubleArray' type=kotlin.DoubleArray origin=null
-          size: CONST Int type=kotlin.Int value=5
-      VAR name:x type:kotlin.collections.DoubleIterator [val]
-        CALL 'public final fun iterator (): kotlin.collections.DoubleIterator declared in kotlin.DoubleArray' type=kotlin.collections.DoubleIterator origin=null
-          $this: GET_VAR 'val a: kotlin.DoubleArray declared in <root>.box' type=kotlin.DoubleArray origin=null
-      VAR name:i type:kotlin.Int [var]
-        CONST Int type=kotlin.Int value=0
-      WHILE label=null origin=WHILE_LOOP
-        condition: CALL 'public abstract fun hasNext (): kotlin.Boolean declared in kotlin.collections.DoubleIterator' type=kotlin.Boolean origin=null
-          $this: GET_VAR 'val x: kotlin.collections.DoubleIterator declared in <root>.box' type=kotlin.collections.DoubleIterator origin=null
-        body: BLOCK type=kotlin.Unit origin=null
-          WHEN type=kotlin.Unit origin=IF
-            BRANCH
-              if: CALL 'public final fun not (): kotlin.Boolean declared in kotlin.Boolean' type=kotlin.Boolean origin=EXCLEQ
-                $this: CALL 'public final fun ieee754equals (arg0: kotlin.Double?, arg1: kotlin.Double?): kotlin.Boolean declared in kotlin.internal.ir' type=kotlin.Boolean origin=EXCLEQ
-                  arg0: CALL 'public final fun get (index: kotlin.Int): kotlin.Double declared in kotlin.DoubleArray' type=kotlin.Double origin=null
-                    $this: GET_VAR 'val a: kotlin.DoubleArray declared in <root>.box' type=kotlin.DoubleArray origin=null
-                    index: GET_VAR 'var i: kotlin.Int declared in <root>.box' type=kotlin.Int origin=null
-                  arg1: CALL 'public final fun next (): kotlin.Double declared in kotlin.collections.DoubleIterator' type=kotlin.Double origin=null
-                    $this: GET_VAR 'val x: kotlin.collections.DoubleIterator declared in <root>.box' type=kotlin.collections.DoubleIterator origin=null
-              then: RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
-                STRING_CONCATENATION type=kotlin.String
-                  CONST String type=kotlin.String value="Fail "
-                  GET_VAR 'var i: kotlin.Int declared in <root>.box' type=kotlin.Int origin=null
-          TYPE_OP type=kotlin.Unit origin=IMPLICIT_COERCION_TO_UNIT typeOperand=kotlin.Unit
-            BLOCK type=kotlin.Int origin=POSTFIX_INCR
-              VAR IR_TEMPORARY_VARIABLE name:tmp_0 type:kotlin.Int [val]
-                GET_VAR 'var i: kotlin.Int declared in <root>.box' type=kotlin.Int origin=null
-              SET_VAR 'var i: kotlin.Int declared in <root>.box' type=kotlin.Unit origin=POSTFIX_INCR
-                CALL 'public final fun inc (): kotlin.Int declared in kotlin.Int' type=kotlin.Int origin=null
-                  $this: GET_VAR 'val tmp_0: kotlin.Int declared in <root>.box' type=kotlin.Int origin=null
-              GET_VAR 'val tmp_0: kotlin.Int declared in <root>.box' type=kotlin.Int origin=null
-      RETURN type=kotlin.Nothing from='public final fun box (): kotlin.String declared in <root>'
-        CONST String type=kotlin.String value="OK"

compiler/testData/ir/irText/regressions/coercionInLoop.fir.kt.txt

@@ -1,17 +0,0 @@
-fun box(): String {
-  val a: DoubleArray = DoubleArray(size = 5)
-  val x: DoubleIterator = a.iterator()
-  var i: Int = 0
-  while (x.hasNext()) { // BLOCK
-    when {
-      ieee754equals(arg0 = a.get(index = i), arg1 = x.next()).not() -> return "Fail " + i
-    }
-    { // BLOCK
-      val tmp_0: Int = i
-      i = tmp_0.inc()
-      tmp_0
-    } /*~> Unit */
-  }
-  return "OK"
-}
-

compiler/testData/ir/irText/regressions/coercionInLoop.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 fun box(): String {
     val a = DoubleArray(5)
     val x = a.iterator()