Make merge script bypass hooks on upload.

TEST=script_test.py
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/558053002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23823 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove guard page mechanism from promotion queue.

BUG=chromium:411210
LOG=n
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/557243002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23824 ce2b1a6d-e550-0410-aec6-3dcde31c8c00