[Mesa-dev] Enable/fix a bunch of OpenGL 4.0-4.3 extensions for compat profile

[Timothy Arceri]

I've send all of these patches out already. The only change is to the
first 2 patches which fixes things so we store a double as 2 unsigned ints
rather than 2 floats.

Everything here has corresponding piglit tests all of which are now 
upstream with the exception of the compute shader display list test.

Our current TODO list has 2 remaining extensions on it before it
should be ok to enable OpenGL 4.4 compat contexts in radeonsi.