glsl: correct compute shader checks for memoryBarrier functions

As per the spec -
"The functions memoryBarrierShared() and groupMemoryBarrier() are
available only in compute shaders; the other functions are available
in all shader types."

Conform to this by adding another delegate to check for compute
shader support instead of only whether the current stage is compute

This allows some fragment shaders in Dirt Rally to compile

Cc: "17.0" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit 21efe2528cd88cb09ba9f69222f69a8ee47611c9)
1 file changed