C++: Fix parsing enum specifier II

This amends the obviously wrong
de975aca4f, which did not honored nameless
enum specifiers.

This fixes e.g. "Find Usages" for declarations following "enum {};".

Change-Id: Id98c074156f576b9a63e6c25dab38721ca34e496
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

tests/auto/cplusplus/ast/tst_ast.cpp

@@ -206,6 +206,7 @@ private slots:
     void invalidCode();
     void enumDeclaration();
     void invalidEnumClassDeclaration();
+    void invalidEnumWithDestructorId();
 };
 
 void tst_AST::gcc_attributes_1()
@@ -2002,6 +2003,14 @@ void tst_AST::invalidEnumClassDeclaration()
     QVERIFY(diag.errorCount != 0);
 }
 
+void tst_AST::invalidEnumWithDestructorId()
+{
+    QSharedPointer<TranslationUnit> unit(parseStatement(
+        "enum ~A {};", false));
+
+    QVERIFY(diag.errorCount != 0);
+}
+
 void tst_AST::initTestCase()
 {
     control.setDiagnosticClient(&diag);