Revert "Handlify JSObject::MigrateInstance and friends."

This is reverted due to mozilla/ecma/Date/15.9.5.9 failing on Windows.

TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/24374002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16900 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
refactor test instruction on ia32

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/23679007

Patch from Weiliang Lin <weiliang.lin2@gmail.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16901 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Allow control intructions to have side effects.

As a first application convert HCompareGeneric to a control Instruction, thus avoid materializing a boolean result value.

BUG=
R=titzer@chromium.org

Review URL: https://codereview.chromium.org/23710070

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16902 ce2b1a6d-e550-0410-aec6-3dcde31c8c00