Several entry points were missing from the .def file. The auto-
generation ensures we remain consistent.

Bug: angleproject:2621
Change-Id: Icb4089c4235f43e76ebd588216d4b988e3a2f0f3
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2552775
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>