FUSED MADD INSTRUCTIONS

The fix for bug #23046775 introduced the -fno-expensive-optimizations
compiler flag on some platforms. This patch lifts that restriction and
instead explicitly turns off fused multiply-add instructions by
setting -ffp-contract=off.

This patch is a contribution from Alexey Kopytov.

(cherry picked from commit a3ebd157e71347d5f654510d752aa699d6808fc7)