Version 3.28.71.16 (merged r23606, r24499)

Fix Date DST computation.

Fix computation of UTC time from local time at DST change points.

BUG=chromium:417640,v8:3116
LOG=N
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/651133002

git-svn-id: https://v8.googlecode.com/svn/branches/3.28@24585 ce2b1a6d-e550-0410-aec6-3dcde31c8c00