Make EXPERIMENTAL_ANNOTATION_ON_OVERRIDE warning till 1.6

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.fir.kt

@@ -0,0 +1,12 @@
+// !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: -OptInOnOverrideForbidden
+
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+annotation class E
+
+class My {
+    @E
+    override fun hashCode() = 0
+}
+

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.kt

@@ -0,0 +1,12 @@
+// !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: -OptInOnOverrideForbidden
+
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+@Retention(AnnotationRetention.BINARY)
+annotation class E
+
+class My {
+    <!EXPERIMENTAL_ANNOTATION_ON_OVERRIDE_WARNING!>@E<!>
+    override fun hashCode() = 0
+}
+

compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnOverrideWarning.txt

@@ -0,0 +1,15 @@
+package
+
+@kotlin.RequiresOptIn(level = Level.WARNING) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class E : kotlin.Annotation {
+    public constructor E()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class My {
+    public constructor My()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    @E public open override /*1*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.fir.kt

@@ -1,4 +1,5 @@
 // !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: +OptInOnOverrideForbidden
 // FILE: api.kt
 
 package api

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.kt

@@ -1,4 +1,5 @@
 // !USE_EXPERIMENTAL: kotlin.RequiresOptIn
+// !LANGUAGE: +OptInOnOverrideForbidden
 // FILE: api.kt
 
 package api