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

^KT-61983 Fixed

compiler/testData/ir/irText/expressions/arrayAugmentedAssignment2.fir.kt.txt

@@ -10,8 +10,8 @@ interface IB {
 
 fun IB.test(a: IA) {
   { // BLOCK
-    val <array>: IA = a
-    val <index_0>: String = ""
-    (<this>, <array>).set(index = <index_0>, value = <array>.get(index = <index_0>).plus(other = 42))
+    val tmp_0: IA = a
+    val tmp_1: String = ""
+    (<this>, tmp_0).set(index = tmp_1, value = tmp_0.get(index = tmp_1).plus(other = 42))
   }
 }