shader/other: Fix hardcoded value in S2R INVOCATION_INFO

Geometry shaders built from Nvidia's compiler check for bits[16:23] to
be less than or equal to 0 with VSETP to default to a "safe" value of
0x8000'0000 (safe from hardware's perspective). To avoid hitting this
path in the shader, return 0x00ff'0000 from S2R INVOCATION_INFO.

This seems to be the maximum number of vertices a geometry shader can
emit in a primitive.