Provide equals/hashCode for Kotlin light classes

KotlinLightClassForExplicitDeclaration already had equals/hashCode, but the
other three implementations of KotlinLightClass did not; this resulted in type
mismatch errors in Java code where the signatures of a super method and the
corresponding sub method wouldn't match because types of parameters were
different

 #KT-8543 Fixed

compiler/light-classes/src/org/jetbrains/kotlin/asJava/FakeLightClassForFileOfPackage.java

@@ -95,4 +95,17 @@ public class FakeLightClassForFileOfPackage extends AbstractLightClass implement
     public Language getLanguage() {
         return JetLanguage.INSTANCE;
     }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (!(obj instanceof FakeLightClassForFileOfPackage)) return false;
+
+        FakeLightClassForFileOfPackage other = (FakeLightClassForFileOfPackage) obj;
+        return file == other.file && delegate.equals(other.delegate);
+    }
+
+    @Override
+    public int hashCode() {
+        return file.hashCode() * 31 + delegate.hashCode();
+    }
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/KotlinWrappingLightClass.java

@@ -202,4 +202,10 @@ public abstract class KotlinWrappingLightClass extends AbstractLightClass implem
     public ItemPresentation getPresentation() {
         return ItemPresentationProviders.getItemPresentation(this);
     }
+
+    @Override
+    public abstract boolean equals(Object obj);
+
+    @Override
+    public abstract int hashCode();
 }