Fix conversion of the SampleMask intrinsic from SPIRV, where it is an array to Metal where it isn't.
Fix conversion of the SampleMask intrinsic from SPIRV, where it is an array to Metal where it isn't.

KhronosGroup/SPIRV-Cross,KhronosGroup/SPIRV-Cross,KhronosGroup/SPIRV-Cross,KhronosGroup/SPIRV-Cross,KhronosGroup/SPIRV-Cross,KhronosGroup/SPIRV-Cross