Add yasm flags for 64-bit mac builds. 

BUG=150760, 150980

Review URL: https://chromiumcodereview.appspot.com/10952023

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: d24206a4e231408592a176cf4a5fe018bf264f64
1 file changed
tree: 6fb0160b415f27ca21bf2fbf2d85fac579579162
  1. README.chromium
  2. source/
  3. yasm.gyp
  4. yasm_compile.gypi