KT-5697 Duplicate Unit type

#KT-5697 Fixed

compiler/backend/src/org/jetbrains/jet/codegen/JvmCodegenUtil.java

@@ -115,7 +115,7 @@ public class JvmCodegenUtil {
     }
 
     private static boolean rawTypeMatches(JetType type, ClassifierDescriptor classifier) {
-        return type.getConstructor().getDeclarationDescriptor().getOriginal() == classifier.getOriginal();
+        return type.getConstructor().equals(classifier.getTypeConstructor());
     }
 
     private static boolean isCallInsideSameClassAsDeclared(@NotNull CallableMemberDescriptor descriptor, @NotNull CodegenContext context) {

compiler/testData/diagnostics/tests/multimodule/duplicateClass/collectionMethodStub.kt

@@ -0,0 +1,20 @@
+// FILE: f1.kt
+
+package kotlin
+
+class Unit
+
+// FILE: f2.kt
+
+class C: MutableIterator<Int> {
+    override fun remove(): Unit {
+        throw UnsupportedOperationException()
+    }
+    override fun next(): Int {
+        throw UnsupportedOperationException()
+    }
+    override fun hasNext(): Boolean {
+        throw UnsupportedOperationException()
+    }
+
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -5372,6 +5372,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/multimodule/duplicateClass"), Pattern.compile("^(.+)\\.kt$"), true);
                 }
                 
+                @TestMetadata("collectionMethodStub.kt")
+                public void testCollectionMethodStub() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/multimodule/duplicateClass/collectionMethodStub.kt");
+                }
+                
                 @TestMetadata("differentGenericArguments.kt")
                 public void testDifferentGenericArguments() throws Exception {
                     doTest("compiler/testData/diagnostics/tests/multimodule/duplicateClass/differentGenericArguments.kt");