FIR: Support overrides of generic-typed members with raw-typed ones

^KT-49070 Fixed

compiler/testData/diagnostics/tests/j+k/rawOverride.kt

@@ -0,0 +1,25 @@
+// SKIP_TXT
+// FIR_IDENTICAL
+
+// FILE: ObjectStubSerializer.java
+import org.jetbrains.annotations.*;
+
+public interface ObjectStubSerializer<Y> {
+    void indexStub(@NotNull Y stub);
+}
+// FILE: StubElement.java
+public interface StubElement<T> {}
+// FILE: IStubFileElementType.java
+import org.jetbrains.annotations.*;
+
+public class IStubFileElementType<X extends StubElement> extends ObjectStubSerializer<X> {
+    @Override
+    // IMO value parameter type should be T (may be I'm wrong)
+    public void indexStub(@NotNull final StubElement stub) {}
+}
+
+// FILE: main.kt
+class MakefileStubFileElementType : IStubFileElementType<StubElement<CharSequence>>() {
+    // FIR: ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED: indexStub, should be ok
+    // FE 1.0: Ok
+}