Roll gyp to r1656

r1656 contains a bug fix for the make generator to correctly regenerate
Makefiles if a gyp was touched. Before, it would assume that it is
running in the top-level directory. However, the v8 standalone build
puts the generated Makefile into the out subdirectory, and so gyp
failed to locate the gyp binary.

BUG=none
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/18053015

Patch from Jochen Eisinger <jochen@chromium.org>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15388 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Introduce a notion of "v8_code" in gyp config files.

This allows for compiling third-party code (such as ICU) with less
strict flags.

BUG=v8:2745
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/18181006

Patch from Jochen Eisinger <jochen@chromium.org>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15389 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Use macros instead of using number directly for x64

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/18076002

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

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15390 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Clean up the usage of V8_TARGET_ARCH_${arch} and V8_HOST_ARCH_${arch}

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/18037002

Patch from Haitao Feng <haitao.feng@intel.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15391 ce2b1a6d-e550-0410-aec6-3dcde31c8c00