X87: Avoid HeapObject check in HStoreNamedField.

port r21509 (78a54b0)

Original commit message:
This way an HStoreNamedField instruction can never deoptimize
itself, which is another important step towards a working
store elimination.

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/306483013

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21547 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
X87: Merge Debugger and Debug.

port r21524 (af88824)

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/298193004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21548 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
X87: Convert String array index/length hash to BitField.

Port r21533 (736c779)

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/298293007

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21549 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
X87: Small changes in preparation for Hydrogen-generated KeyedLoadGeneric

Port r21535(8bb4c2b)

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/302453011

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21550 ce2b1a6d-e550-0410-aec6-3dcde31c8c00