IR: do not copy call in ForLoopsLowering

This is just a refactoring/optimization that makes use of the fact that
IrCall.symbol is now mutable.

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/loops/ForLoopsLowering.kt

@@ -17,12 +17,14 @@ import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
 import org.jetbrains.kotlin.ir.declarations.IrSymbolOwner
 import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
 import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.types.isNothing
 import org.jetbrains.kotlin.ir.types.isStrictSubtypeOfClass
-import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.ir.util.dump
+import org.jetbrains.kotlin.ir.util.functions
+import org.jetbrains.kotlin.ir.util.hasEqualFqName
+import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.ir.visitors.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.util.OperatorNameConventions
@@ -343,14 +345,10 @@ private class RangeLoopTransformer(
         val loopCondition = loop.condition as? IrCall ?: return
         loopCondition.dispatchReceiver?.type = receiverType
 
-        val nextCall = loopVariable.initializer as? IrCall ?: return
-        loopVariable.initializer = with(nextCall) {
-            IrCallImpl(
-                startOffset, endOffset, type, next.symbol, typeArgumentsCount, valueArgumentsCount, origin, superQualifierSymbol
-            ).apply {
-                copyTypeAndValueArgumentsFrom(nextCall)
-                dispatchReceiver?.type = receiverType
-            }
+        val nextCall = loopVariable.initializer
+        if (nextCall is IrCall) {
+            nextCall.symbol = next.symbol
+            nextCall.dispatchReceiver?.type = receiverType
         }
     }