Introduce FIR_IDENTICAL for FIR vs old frontend tests #KT-36879 Fixed

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/recursiveContractCustomContractFunction.fir.kt

@@ -1,39 +0,0 @@
-// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
-// !LANGUAGE: +UseReturnsEffect
-// Issue: KT-26386
-
-fun myRun(block: () -> Unit) {
-    block()
-}
-
-fun contract(block: () -> Unit) {
-    block()
-}
-
-fun case_1(): Boolean? {
-    contract { case_1() }
-    return null
-}
-
-fun case_2(): Boolean? {
-    contract { case_3() }
-    return null
-}
-
-fun case_3(): Boolean? {
-    contract { case_2() }
-    return null
-}
-
-fun case4() {
-    contract {
-        myRun {
-            val s: String
-            run {
-                s = "hello"
-            }
-            s.length
-        }
-    }
-}
-

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/recursiveContractCustomContractFunction.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
 // !LANGUAGE: +UseReturnsEffect
 // Issue: KT-26386