Don't use anonymous types declared in an anonymous union.

They are a non-standard extension (probably in C1X, IIRC), but clang is unhappy
with them when -Wnested-anon-types is enabled, which seems to be implied by
-pedantic.

With this change and the previous fix for clang, we are now -Werror clean, even
on clang 3.3.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/14850016

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14659 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove HIsNilAndBranch (it's now unused)

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/14971005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14660 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Improve dead code elimination by transitively marking live code and removing all dead code. Replace unreachable phi removal algorithm with the new dead code elimination pass, which is more thorough.

Review URL: https://codereview.chromium.org/14676011

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14661 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Avoid convertion to double when it is not needed.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/15162002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14664 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Error found in test262 on ARM: BinaryOpStub could call out to a built-in and push parameters without an enclosing frame. This corrupted stackwalking.

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/14813029

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14665 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge commit '15349aacf314a257c3e05485011f59e60bd6c45e' into hj-dev-palfia
MIPS: Error found in test262 on ARM: BinaryOpStub could call out to a built-in and push parameters without an enclosing frame.

Port r14665 (15349aa)

This corrupted stackwalking.