Switch label: do not resolve unqualified enum constants referenced on the right side of arrow

Fixes IDEA-210771 Error message should be exposed for the new 'case' label in Java 12 in case of wrong constant usage

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiSwitchLabelStatementBaseImpl.java

@@ -44,7 +44,7 @@ public abstract class PsiSwitchLabelStatementBaseImpl extends CompositePsiElemen
                                      @NotNull ResolveState state,
                                      PsiElement lastParent,
                                      @NotNull PsiElement place) {
-    if (lastParent != null) {
+    if (lastParent instanceof PsiExpressionList) {
       PsiSwitchBlock switchStatement = getEnclosingSwitchBlock();
       if (switchStatement != null) {
         PsiExpression expression = switchStatement.getExpression();

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting12/SwitchExpressionsEnumResolve.java

@@ -0,0 +1,12 @@
+import java.util.Random;
+
+class SwitchExpressionsEnumResolve {
+  enum E { E1, E2 }
+  
+  E test(E e) {
+    return switch (e) {
+      case E1 -> <error descr="Cannot resolve symbol 'E2'">E2</error>;
+      case E2 -> <error descr="Cannot resolve symbol 'E1'">E1</error>;
+    };
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/LightJava12HighlightingTest.kt

@@ -10,6 +10,7 @@ class LightJava12HighlightingTest : LightCodeInsightFixtureTestCase() {
 
   fun testEnhancedSwitchStatements() = doTest()
   fun testSwitchExpressions() = doTest()
+  fun testSwitchExpressionsEnumResolve() = doTest()
   fun testValueBreaks() = doTest()
   fun testSwitchNumericPromotion() = doTest()
   fun testSimpleInferenceCases() = doTest()