docs: mark off nv50/nvc0 for ARB_sample_shading, update relnotes

relnotes weren't updated this whole time, so I went through all the
GL3.txt changes and picked out the nouveau ones since 10.1.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
glsl: fix spelling of derived

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
glsl: Clean up apply_implicit_conversion

We're about to add new implicit conversions, first for ARB_gpu_shader5,
and then later for ARB_gpu_shader_fp64. Pull out the opcode
determination into its own function, and get rid of the bool -> float
case that could never be hit anyway [since it fails the is_numeric()
check].

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
glsl: Add support for int -> uint implicit conversions

This is required for ARB_gpu_shader5.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
glsl: Pass parse state to parameter_lists_match()

The available implicit conversions depend on the GLSL version we're
compiling.

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
glsl: Pass parse state to can_implicitly_convert_to()

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
glsl: Allow int -> uint implicit conversions on function parameters

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>