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

compiler/testData/diagnostics/testsWithStdLib/native/noBody.fir.kt

@@ -1,25 +0,0 @@
-import kotlin.jvm.*
-
-external fun foo()
-
-class C {
-    external fun foo()
-
-    companion object {
-        external fun foo()
-    }
-}
-
-object O {
-    external fun foo()
-}
-
-fun test() {
-    class Local {
-        external fun foo()
-    }
-
-    object {
-        external fun foo()
-    }
-}

compiler/testData/diagnostics/testsWithStdLib/native/noBody.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 import kotlin.jvm.*
 
 external fun foo()

compiler/testData/diagnostics/testsWithStdLib/native/override.fir.kt

@@ -1,9 +0,0 @@
-import kotlin.jvm.*
-
-interface Base {
-    fun foo()
-}
-
-class Derived : Base {
-    override external fun foo()
-}

compiler/testData/diagnostics/testsWithStdLib/native/override.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 import kotlin.jvm.*
 
 interface Base {