Generate the proper error when a constant refers to itself.

pkg/analyzer/test/generated/compile_time_error_code_test.dart

Index: pkg/analyzer/test/generated/compile_time_error_code_test.dart
diff --git a/pkg/analyzer/test/generated/compile_time_error_code_test.dart b/pkg/analyzer/test/generated/compile_time_error_code_test.dart
index 3f6b77ca6c9c35e31a4507032f6f85bd9ce5c5ad..abea165f789d5dede42bcc438a13f4188918165c 100644
--- a/pkg/analyzer/test/generated/compile_time_error_code_test.dart
+++ b/pkg/analyzer/test/generated/compile_time_error_code_test.dart
@@ -4685,6 +4685,16 @@ class C {
     verify([source]);
   }
 
+  void test_recursiveCompileTimeConstant_singleVariable() {
+    Source source = addSource(r'''
+const x = x;
+''');
+    resolve(source);
+    assertErrors(
+        source, [CompileTimeErrorCode.RECURSIVE_COMPILE_TIME_CONSTANT]);
+    verify([source]);
+  }
+
   void test_recursiveConstructorRedirect() {
     Source source = addSource(r'''
 class A {