KT-33132: Add diagnostics test showing that issue is fixed in K2

^KT-33132: Fixed

compiler/testData/diagnostics/tests/operatorsOverloading/EqualsOperatorOverrideHierarchies.fir.kt

@@ -0,0 +1,25 @@
+open class Parent {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+open class OperatorParent {
+    override operator fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+
+class A : Parent() {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+class B : OperatorParent() {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+class C : Parent() {
+    override operator fun equals(other: Any?): Boolean = // false positive in K1, OK in K2
+        super.equals(other) //
+}
+class D : OperatorParent() {
+    override operator fun equals(other: Any?): Boolean = // false positive in K1, OK in K2
+        super.equals(other)
+}

compiler/testData/diagnostics/tests/operatorsOverloading/EqualsOperatorOverrideHierarchies.kt

@@ -0,0 +1,25 @@
+open class Parent {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+open class OperatorParent {
+    override operator fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+
+class A : Parent() {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+class B : OperatorParent() {
+    override fun equals(other: Any?): Boolean =
+        super.equals(other)
+}
+class C : Parent() {
+    override <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun equals(other: Any?): Boolean = // false positive in K1, OK in K2
+        super.equals(other) //
+}
+class D : OperatorParent() {
+    override <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun equals(other: Any?): Boolean = // false positive in K1, OK in K2
+        super.equals(other)
+}

compiler/testData/diagnostics/tests/operatorsOverloading/EqualsOperatorOverrideHierarchies.txt

@@ -0,0 +1,43 @@
+package
+
+public final class A : Parent {
+    public constructor A()
+    public open override /*1*/ 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 B : OperatorParent {
+    public constructor B()
+    public open override /*1*/ 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 C : Parent {
+    public constructor C()
+    public open override /*1*/ 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 D : OperatorParent {
+    public constructor D()
+    public open override /*1*/ 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 open class OperatorParent {
+    public constructor OperatorParent()
+    public open override /*1*/ 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 open class Parent {
+    public constructor Parent()
+    public open override /*1*/ 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
+}