Implemented EGL_KHR_create_context as described here:
www.khronos.org/registry/egl/extensions/KHR/EGL_KHR_create_context.txt

A small part of it was already implemented, which was to add
support for the EGL_OPENGL_ES3_BIT bit in the EGL_RENDERABLE_TYPE
bitfield. Note that the EGL_OPENGL_ES3_BIT is explicitly disabled
on Android right now.

Change-Id: I10e6222511b29f2d91bd55bfeb0f39bc5b884f89
Reviewed-on: https://swiftshader-review.googlesource.com/5380Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>