Remove a reference to __DATE__ from yasm for non official builds. clone of https://codereview.chromium.org/760623005/ but with a different base url... TBR=maruel@chromium.org Review URL: https://codereview.chromium.org/761753002 git-svn-id: http://src.chromium.org/svn/trunk/deps/third_party/yasm/patched-yasm@293123 4ff67af0-8c30-449e-8e8b-ad334ec8d88c