Navigation to implementation: do not try to find expect enum inheritors

Before this commit, expect enum could find actual enum entries
as its implementation, now it cannot.
#KT-28206 Fixed

idea/src/org/jetbrains/kotlin/idea/search/ideaExtensions/KotlinDefinitionsSearcher.kt

@@ -50,7 +50,12 @@ class KotlinDefinitionsSearcher : QueryExecutor<PsiElement, DefinitionsScopedSea
 
         return when (element) {
             is KtClass -> {
-                processClassImplementations(element, consumer) && processActualDeclarations(element, consumer)
+                val isExpectEnum = runReadAction { element.isEnum() && element.isExpectDeclaration() }
+                if (isExpectEnum) {
+                    processActualDeclarations(element, consumer)
+                } else {
+                    processClassImplementations(element, consumer) && processActualDeclarations(element, consumer)
+                }
             }
 
             is KtObjectDeclaration -> {

idea/testData/navigation/implementations/multiModule/expectEnumEntry/common/Some.kt

@@ -0,0 +1,8 @@
+package test
+
+expect enum class <caret>Some {
+    FIRST,
+    SECOND
+}
+
+// REF: [testModule_JVM] (test).Some

idea/testData/navigation/implementations/multiModule/expectEnumEntry/jvm/Some.kt

@@ -0,0 +1,6 @@
+package test
+
+actual enum class Some(val x: Int) {
+    FIRST(1),
+    SECOND(2)
+}

idea/tests/org/jetbrains/kotlin/idea/navigation/KotlinGotoImplementationMultiModuleTestGenerated.java

@@ -64,6 +64,11 @@ public class KotlinGotoImplementationMultiModuleTestGenerated extends AbstractKo
         runTest("idea/testData/navigation/implementations/multiModule/expectCompanion/");
     }
 
+    @TestMetadata("expectEnumEntry")
+    public void testExpectEnumEntry() throws Exception {
+        runTest("idea/testData/navigation/implementations/multiModule/expectEnumEntry/");
+    }
+
     @TestMetadata("expectObject")
     public void testExpectObject() throws Exception {
         runTest("idea/testData/navigation/implementations/multiModule/expectObject/");