Bug 1445683 - Add support for SSE 4.2 to libaom moz.build; r=chmanchester

MozReview-Commit-ID: 76yhREntUzj

--HG--
extra : rebase_source : 3e7c9582d725a42955cc38a5fe209ad5aed49009

media/libaom/moz.build

@@ -114,6 +114,8 @@ if CONFIG['CC_TYPE'] != 'msvc':
             SOURCES[f].flags += ['-mssse3']
         elif f.endswith('sse4.c'):
             SOURCES[f].flags += ['-msse4.1']
+        elif f.endswith('sse42.c'):
+            SOURCES[f].flags += ['-msse4.2']
         elif f.endswith('avx.c'):
             SOURCES[f].flags += ['-mavx']
         elif f.endswith('avx2.c'):