Add vm672-m1 (the new Mac ASan builder) to the list of machines using pinned Clang version.

BUG=170629
TBR=thakis
Review URL: https://codereview.chromium.org/12729006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@188080 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed