- Move the entry points common to GLES1/2 to GLES2 since GLES2 is the
primary use case and we want to isolate the GLES1-only bits.
- Update entry points with all the wanted extensions for Android.
- Auto-generate GLES1-specific entry points and use them as a macro in
Context.h.
- Move all GLES1-specific renderer implementations to ContextGLES1.cpp

+ Fix getting pointer params in generate_entry_points.py

BUG=angleproject:2306

Change-Id: If32bfd2b63657acecaec6adb10cabf39f06c4832
Reviewed-on: https://chromium-review.googlesource.com/959630Reviewed-by: Lingfeng Yang <lfy@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Lingfeng Yang <lfy@google.com>