The stack frame iteration during GC was missing one slot in stub frames that
did not save the pool pointer.
- This change makes all stub frames uniform, i.e they always save/restore the pool pointer. This ensures that we will traverse all slots on the stack.
- A new constant called kFirstObjectSlotFromFp has been added which is used as the slot to start stack traversal.
(The ARM and MIPs changes will be in a different CL)
R=iposva@google.com, regis@google.com, zra@google.com
Review URL: https://codereview.chromium.org//63093003
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@30088 260f80e4-7a28-3924-810f-c04153c831b5