mesa: Make compile_shader() take a gl_shader, not a GLuint.
mesa: Make compile_shader() take a gl_shader, not a GLuint.

In half the callers, we already have a pointer, and don't need
to look it up again.  This will also help with upcoming meta work.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Timothy Arceri <5dd83789ef3714029244367ba1ca09f1d7627408@collabora.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler