Implement glGetPointerv(). Bug 26794307 Change-Id: I0aa175f091550d544a33503b602c191353e7a1c5 Reviewed-on: https://swiftshader-review.googlesource.com/4606 Tested-by: Nicolas Capens <capn@google.com> Reviewed-by: Nicolas Capens <capn@google.com>