Implement OpenGL single-color specular lighting.

Change-Id: I40f9ad720bdbd93c44be8fb991dfbf055a3eceba
Reviewed-on: https://swiftshader-review.googlesource.com/3803
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
5 files changed