mesa/main: do not allow illegal enums for ConservativeRasterParameter[if]NV
The NV_conservative_raster_pre_snap_triangles
spec allows
CONSERVATIVE_RASTER_MODE_NV
for ConservativeRasterParameteriNV
, but not
for ConservativeRasterParameterfNV
.
Similarly, the NV_conservative_raster_dilate
spec allows
CONSERVATIVE_RASTER_DILATE_NV
for ConservativeRasterParameterfNV
, but
not for ConservativeRasterParameteriNV
.
These two functions hare no overlapping state they can set. So let's split them in two, so we don't confuse their implementations.