Finer grain control over specifying which variables have invalid constant initializers.

pkg/analyzer/lib/src/summary/resynthesize.dart

Index: pkg/analyzer/lib/src/summary/resynthesize.dart
diff --git a/pkg/analyzer/lib/src/summary/resynthesize.dart b/pkg/analyzer/lib/src/summary/resynthesize.dart
index 4fdd54e4abe956dd1f078f315ca8b8522698c096..891300e27ede08d486603db82654905a0029b383 100644
--- a/pkg/analyzer/lib/src/summary/resynthesize.dart
+++ b/pkg/analyzer/lib/src/summary/resynthesize.dart
@@ -286,6 +286,9 @@ class _ConstExprBuilder {
   Expression get expr => stack.single;
 
   Expression build() {
+    if (!uc.isValidConst) {
+      return AstFactory.identifier3(r'$$invalidConstExpr$$');
+    }
     for (UnlinkedConstOperation operation in uc.operations) {
       switch (operation) {
         case UnlinkedConstOperation.pushNull:
@@ -459,7 +462,8 @@ class _ConstExprBuilder {
         case UnlinkedConstOperation.typeCast:
         case UnlinkedConstOperation.typeCheck:
         case UnlinkedConstOperation.throwException:
-          return AstFactory.identifier3(r'$notConst$');
+          throw new UnimplementedError(
+              'Unexpected $operation in a constant expression.');
       }
     }
     return stack.single;