When using floats, when testing INT_MAX, the loss of precision causes
an undefined behavior when casting from float to int. In this cause on
clang 3.6 on Mac, the integer wrapped and became INT_MIN.

BUG=angleproject:891

Change-Id: Ieb3199fd33c25e7da8d154f88658e06f01d53c0e
Reviewed-on: https://chromium-review.googlesource.com/303338
Tryjob-Request: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>