VM: Fix crash when a type error is encountered while evaluating metadata in checked mode.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 2e4ecaa55f17e714509c5549154c6f65cd01db71..dc0ac917aefcdb8c3b41b941079112e2990d8483 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -8945,8 +8945,11 @@ RawObject* Parser::EvaluateConstConstructorCall(
   if (result.IsError()) {
       // An exception may not occur in every parse attempt, i.e., the
       // generated AST is not deterministic. Therefore mark the function as
-      // not optimizable.
-      current_function().SetIsOptimizable(false);
+      // not optimizable. Unless we are evaluating metadata, in which case there
+      // is no current function.
+      if (!parsing_metadata_) {
+        current_function().SetIsOptimizable(false);
+      }
       if (result.IsUnhandledException()) {
         return result.raw();
       } else {