Imports from objects: Do not create new instances on getOriginal every time

Also fixes a problem where DeclarationLookupObjectImpl didn't have stable hashCode

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

@@ -0,0 +1,15 @@
+package a
+
+import a.O.uniqueName
+
+object O {
+    fun uniqueName() {
+    }
+}
+
+fun main() {
+    uniqueN<caret>
+}
+
+// EXIST: uniqueName
+// NUMBER: 1

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

@@ -223,6 +223,12 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             doTest(fileName);
         }
 
+        @TestMetadata("ImportedMemberFromObject.kt")
+        public void testImportedMemberFromObject() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/ImportedMemberFromObject.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("InCallExpression.kt")
         public void testInCallExpression() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InCallExpression.kt");

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

@@ -223,6 +223,12 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("ImportedMemberFromObject.kt")
+        public void testImportedMemberFromObject() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/ImportedMemberFromObject.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("InCallExpression.kt")
         public void testInCallExpression() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/common/InCallExpression.kt");