Do not report "accidental overrides" when "override" modifier is specified

compiler/testData/diagnostics/tests/duplicateJvmSignature/accidentalOverrides/overridesNothing.kt

@@ -0,0 +1,7 @@
+trait B {
+    fun getX() = 1
+}
+
+class C : B {
+    <!NOTHING_TO_OVERRIDE!>override<!> val x = 1
+}

compiler/testData/diagnostics/tests/override/Generics.kt

@@ -42,7 +42,7 @@ abstract class MyAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {
 
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
-    <!ACCIDENTAL_OVERRIDE!><!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R)<!> = r
+    <!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R) = r
     <!CONFLICTING_OVERLOADS!><!NOTHING_TO_OVERRIDE!>override<!> val <T> pr : R<!> = r
 }
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}