- Do not attempt to set parameter types if they

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 41173)
+++ runtime/vm/object.cc	(working copy)
@@ -5459,6 +5459,8 @@
 void Function::SetParameterTypeAt(
     intptr_t index, const AbstractType& value) const {
   ASSERT(!value.IsNull());
+  // Method extractor parameters are in the VM heap.
+  ASSERT(kind() != RawFunction::kMethodExtractor);
   const Array& parameter_types = Array::Handle(raw_ptr()->parameter_types_);
   parameter_types.SetAt(index, value);
 }