Makefile's: add/remove/re-organize optimization flags
-Ofast
Disregard strict standards compliance. -Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs. It turns on -ffast-math and the Fortran-specific -fno-protect-parens and -fstack-arrays.

-fpredictive-commoning
Perform predictive commoning optimization, i.e., reusing computations (especially memory loads and stores) performed in previous iterations of loops.

-fgcse-las
When -fgcse-las is enabled, the global common subexpression elimination pass eliminates redundant loads that come after stores to the same memory location (both partial and full redundancies).

For more info:

http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html

Signed-off-by: Jean Francis Dominique S. Mabalot <jfdsmabalot@redhat.com>