KT-3525 Duplicate inner class name not detected

#KT-3525 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/resolve/DeclarationResolver.java

@@ -346,7 +346,13 @@ public class DeclarationResolver {
     }
 
     private void checkRedeclarationsInInnerClassNames() {
-        for (MutableClassDescriptor classDescriptor : context.getClasses().values()) {
+        Iterable<MutableClassDescriptor> classesAndObjects = Iterables.concat(context.getClasses().values(), context.getObjects().values());
+        for (MutableClassDescriptor classDescriptor : classesAndObjects) {
+            if (classDescriptor.getKind() == ClassKind.CLASS_OBJECT) {
+                // Class objects should be considered during analysing redeclarations in classes
+                continue;
+            }
+
             Collection<DeclarationDescriptor> allDescriptors = classDescriptor.getScopeForMemberLookup().getOwnDeclaredDescriptors();
 
             MutableClassDescriptorLite classObj = classDescriptor.getClassObjectDescriptor();

compiler/testData/diagnostics/tests/redeclarations/RedeclarationsInObjects.kt

@@ -0,0 +1,8 @@
+// KT-3525
+object B {
+    class <!REDECLARATION!>C<!>
+    class <!REDECLARATION!>C<!>
+
+    val <!REDECLARATION!>a<!> : Int = 1
+    val <!REDECLARATION!>a<!> : Int = 1
+}

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

@@ -3468,6 +3468,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/redeclarations/Redeclarations.kt");
             }
             
+            @TestMetadata("RedeclarationsInObjects.kt")
+            public void testRedeclarationsInObjects() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/redeclarations/RedeclarationsInObjects.kt");
+            }
+            
             @TestMetadata("RedeclaredTypeParameters.kt")
             public void testRedeclaredTypeParameters() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/redeclarations/RedeclaredTypeParameters.kt");