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

^KT-61983 Fixed

compiler/testData/ir/irText/declarations/contextReceivers/compoundAssignmentOperators.fir.kt.txt

@@ -33,9 +33,9 @@ data class Result {
     when {
       other !is Result -> return false
     }
-    val tmp0_other_with_cast: Result = other as Result
+    val tmp_0: Result = other as Result
     when {
-      EQEQ(arg0 = <this>.#i, arg1 = tmp0_other_with_cast.#i).not() -> return false
+      EQEQ(arg0 = <this>.#i, arg1 = tmp_0.#i).not() -> return false
     }
     return true
   }