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

^KT-61983 Fixed

compiler/testData/ir/irText/js/dynamic/dynamicElvisOperator.kt.txt

@@ -1,9 +1,9 @@
 fun test(d: dynamic): dynamic {
   return { // BLOCK
-    val tmp0_elvis_lhs: dynamic = d
+    val tmp_0: dynamic = d
     when {
-      EQEQ(arg0 = tmp0_elvis_lhs, arg1 = null) -> "other"
-      else -> tmp0_elvis_lhs
+      EQEQ(arg0 = tmp_0, arg1 = null) -> "other"
+      else -> tmp_0
     }
   }
 }