Fix VM crash when parsing what looks like a closure call during metadata evaluation.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 907e0ac05f6a1304a8d5e6ea3feb9cad127d871d..085bce208ae8a612e32d2f03f13a3cfe10280f48 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -8570,6 +8570,10 @@ AstNode* Parser::ParseSelectors(AstNode* primary, bool is_cascade) {
       } else {
         // Left is not a primary node; this must be a closure call.
         AstNode* closure = left;
+        if (parsing_metadata_) {

[hausner, 2014/02/27 22:50:25]

It would still be good to have an explanation here why we need the special case
for parsing metadata.

[rmacnak, 2014/02/27 23:23:30]

Done.

+            ErrorMsg(closure->token_pos(),
+              "expression is not a valid compile-time constant");
+        }
         selector = ParseClosureCall(closure);
       }
     } else {