Entry points were generated using scripts which take the
new function declarations from gl31.h, find the newly added functions
and output the new function declarations and defitions.

BUG=angleproject:1442
TEST=angle_unittests

Change-Id: I2d77eb4cc24873a31cb2745b7b82bf611d5058c6
Reviewed-on: https://chromium-review.googlesource.com/361291Reviewed-by: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>