[FIR TEST] Add bad test data (submitted KT-38400)

compiler/testData/diagnostics/tests/thisAndSuper/unqualifiedSuper/withMethodOfAnyOverridenInInterface.fir.kt

@@ -0,0 +1,8 @@
+interface IWithToString {
+    override fun toString(): String
+}
+
+class A : IWithToString {
+    // Should be Any#toString(), even though IWithToString defines an abstract toString.
+    override fun toString(): String = super.<!ABSTRACT_SUPER_CALL!>toString<!>()
+}

compiler/testData/diagnostics/tests/thisAndSuper/unqualifiedSuper/withMethodOfAnyOverridenInInterface.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 interface IWithToString {
     override fun toString(): String
 }