R600: Expand vector float operations for both SI and R600

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
R600: Expand vector FFLOOR ops

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
R600: Expand vector FRINT ops

Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>