Using the `__builtin_elementwise_(add|sub)_sat` functions allows us to
directly optimize to the desired intrinsic, and avoid scalarization for
vector types.
v2: - use quotes instead of <>
- add include to r600/lib/math/nextafter.c changed
Reviewed-by: Tom Stellard <tom@stellard.net>
Reviewed-by: Aaron Watry <awatry@gmail.com>
llvm-svn: 211576
