mac: Faster bit testing for EXC_GUARD exception “flavors”
mac: Faster bit testing for EXC_GUARD exception “flavors”

After e7630628e9c9, I thought “isn’t there a standard library function
for that?” There is!

Change-Id: I284c7fdf8535c4fc53100e80fceb363bf2afee93
Reviewed-on: https://chromium-review.googlesource.com/431856
Reviewed-by: Scott Graham <e134406e1863f3b48b0795831afac5c0595efb36@chromium.org>

chromium/crashpad,atom/crashpad,atom/crashpad,chromium/crashpad,chromium/crashpad,atom/crashpad