First step towards implementing stack map descriptions for the optimizing compiler.

vm/raw_object.cc

Index: vm/raw_object.cc
===================================================================
--- vm/raw_object.cc	(revision 5501)
+++ vm/raw_object.cc	(working copy)
@@ -137,6 +137,12 @@
         instance_size = PcDescriptors::InstanceSize(num_descriptors);
         break;
       }
+      case kStackmap: {
+        const RawStackmap* map = reinterpret_cast<const RawStackmap*>(this);
+        intptr_t size_in_bytes = Smi::Value(map->ptr()->bitmap_size_in_bytes_);
+        instance_size = Stackmap::InstanceSize(size_in_bytes);
+        break;
+      }
       case kLocalVarDescriptors: {
         const RawLocalVarDescriptors* raw_descriptors =
             reinterpret_cast<const RawLocalVarDescriptors*>(this);
@@ -372,6 +378,15 @@
 }
 
 
+intptr_t RawStackmap::VisitStackmapPointers(RawStackmap* raw_obj,
+                                            ObjectPointerVisitor* visitor) {
+  RawStackmap* obj = raw_obj->ptr();
+  intptr_t size_in_bytes = Smi::Value(obj->bitmap_size_in_bytes_);
+  visitor->VisitPointers(raw_obj->from(), raw_obj->to());
+  return Stackmap::InstanceSize(size_in_bytes);
+}
+
+
 intptr_t RawLocalVarDescriptors::VisitLocalVarDescriptorsPointers(
     RawLocalVarDescriptors* raw_obj, ObjectPointerVisitor* visitor) {
   RawLocalVarDescriptors* obj = raw_obj->ptr();
@@ -661,5 +676,4 @@
   return JSRegExp::InstanceSize(length);
 }
 
-
 }  // namespace dart