llvmpipe: align scratch size to 64-bit size.
This fixes a crash with luxmark where it uses a 12-bit scratch space, but when llvmpipe allocates it for 8 lanes, it isn't properly aligned for 64-bit.
Karol found this debugging rusticl.
This fixes a crash with luxmark where it uses a 12-bit scratch space, but when llvmpipe allocates it for 8 lanes, it isn't properly aligned for 64-bit.
Karol found this debugging rusticl.