Make sure the signature of the call method is finalized before involving it

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index b5875683191fbd785afbaa64640fd4a829764675..9e1d5032bca59832bfe0ddd400c7fde1e3f4c3fd 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -1162,6 +1162,7 @@ class Class : public Object {
   RawFunction* LookupFunctionAllowPrivate(const String& name) const;
   RawFunction* LookupGetterFunction(const String& name) const;
   RawFunction* LookupSetterFunction(const String& name) const;
+  RawFunction* LookupCallFunctionForTypeTest() const;
   RawField* LookupInstanceField(const String& name) const;
   RawField* LookupStaticField(const String& name) const;
   RawField* LookupField(const String& name) const;
@@ -6216,7 +6217,7 @@ class BoundedType : public AbstractType {
     // uninstantiated upper bound. Therefore, we do not need to check if the
     // bound is instantiated. Moreover, doing so could lead into cycles, as in
     // class C<T extends C<C>> { }.
-    return AbstractType::Handle(type()).IsInstantiated();
+    return AbstractType::Handle(type()).IsInstantiated(trail);
   }
   virtual bool IsEquivalent(const Instance& other, TrailPtr trail = NULL) const;
   virtual bool IsRecursive() const;