[IR] Normalize temp var names in Kotlin-like dump

^KT-61983 Fixed

compiler/testData/ir/irText/expressions/callableReferences/withVarargViewedAsArray.kt.txt

@@ -1,9 +1,9 @@
 fun sum(vararg args: Int): Int {
   var result: Int = 0
   { // BLOCK
-    val tmp0_iterator: IntIterator = args.iterator()
-    while (tmp0_iterator.hasNext()) { // BLOCK
-      val arg: Int = tmp0_iterator.next()
+    val tmp_0: IntIterator = args.iterator()
+    while (tmp_0.hasNext()) { // BLOCK
+      val arg: Int = tmp_0.next()
       result = result.plus(other = arg)
     }
   }