Migrate instance of deprecated maps in HCheckMaps.

Currently only direct map checks are supported. Otherwise only polymorphic cases with a generic fallback behave properly, regular polymorphic cases still need to be adapted.

R=danno@chromium.org

Review URL: https://chromiumcodereview.appspot.com/21536003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16057 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Use first hit when dumping heap constants.

This makes sure that the first hit is used when dumping heap constants
and hence "TheHoleValue" is not overwritten with other roots that are
initialized to the hole as well.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/21639004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16058 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Change environment padding value to value with smi representation.

BUG=
R=ulan@chromium.org

Review URL: https://chromiumcodereview.appspot.com/22226002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16059 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
MIPS: Replace HCheckPrototypeMaps by explicit map checks of constant values.

Port r16055 (7567e57f)

BUG=

Review URL: https://codereview.chromium.org/21639003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16060 ce2b1a6d-e550-0410-aec6-3dcde31c8c00