Intel Mac has the same bug as Win. So the CL enables it in GLSL translator as
well.

BUG=chromium:642605
TEST=deqp/functional/gles3/shadertexturefunction/texelfetchoffset.html

Change-Id: I30323ea3a6d4c07ff32e50bd7c574916b5b865f4
Reviewed-on: https://chromium-review.googlesource.com/378601Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>