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

^KT-61983 Fixed

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

@@ -2,9 +2,9 @@ fun test(b: Boolean, i: Int) {
   when {
     b -> { // BLOCK
       { // BLOCK
-        val tmp0_subject: Int = i
+        val tmp_0: Int = i
         when {
-          EQEQ(arg0 = tmp0_subject, arg1 = 0) -> 1
+          EQEQ(arg0 = tmp_0, arg1 = 0) -> 1
           else -> null
         }
       }