nir/spirv: Lower gl_GlobalInvocationID correctly
nir/spirv: Lower gl_GlobalInvocationID correctly

Use nir_intrinsic_load_local_invocation_id, not
nir_intrinsic_load_invocation_id (missing 'local'), which is a geometry
shader built-in.

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler