Fix invocation of closures via .call in the VM

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 33570)
+++ runtime/vm/object.h	(working copy)
@@ -1541,6 +1541,10 @@
     return kind() == RawFunction::kInvokeFieldDispatcher;
   }
 
+  bool IsInvokeClosureDispatcher() const {
+    return kind() == RawFunction::kInvokeClosureDispatcher;
+  }
+
   // Returns true iff an implicit closure function has been created
   // for this function.
   bool HasImplicitClosureFunction() const {
@@ -1593,6 +1597,7 @@
       case RawFunction::kMethodExtractor:
       case RawFunction::kNoSuchMethodDispatcher:
       case RawFunction::kInvokeFieldDispatcher:
+      case RawFunction::kInvokeClosureDispatcher:
         return true;
       case RawFunction::kClosureFunction:
       case RawFunction::kConstructor: