KT-10664 No code completion after variable initialized with elvis

#KT-10664 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/SmartCastManager.java

@@ -73,12 +73,12 @@ public class SmartCastManager {
             @NotNull DeclarationDescriptor containingDeclarationOrModule,
             @NotNull DataFlowInfo dataFlowInfo
     ) {
-        final List<KotlinType> variants = getSmartCastVariants(receiverToCast, bindingContext,
-                                                               containingDeclarationOrModule, dataFlowInfo);
+        final List<KotlinType> variants = CollectionsKt.distinct(
+                getSmartCastVariants(receiverToCast, bindingContext, containingDeclarationOrModule, dataFlowInfo));
         return CollectionsKt.filter(variants, new Function1<KotlinType, Boolean>() {
             @Override
             public Boolean invoke(final KotlinType type) {
-                return !CollectionsKt.any(variants, new Function1<KotlinType, Boolean>() {
+                return CollectionsKt.none(variants, new Function1<KotlinType, Boolean>() {
                     @Override
                     public Boolean invoke(KotlinType another) {
                         return another != type && KotlinTypeChecker.DEFAULT.isSubtypeOf(another, type);

idea/idea-completion/testData/basic/common/KT10664.kt

@@ -0,0 +1,9 @@
+fun foo(): String? = null
+
+fun bar() {
+    val f = foo() ?: return
+    f.<caret>
+}
+
+// EXIST: length
+// EXIST: hashCode

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JSBasicCompletionTestGenerated.java

@@ -463,6 +463,12 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             doTest(fileName);
         }
 
+        @TestMetadata("KT10664.kt")
+        public void testKT10664() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/KT10664.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("LocalMultideclarationValues.kt")
         public void testLocalMultideclarationValues() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/LocalMultideclarationValues.kt");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -463,6 +463,12 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("KT10664.kt")
+        public void testKT10664() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/KT10664.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("LocalMultideclarationValues.kt")
         public void testLocalMultideclarationValues() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/LocalMultideclarationValues.kt");