Remove obsolete compiler flags
Needed to remove the obsolete fopenmp-simd flag that also doesn't work on clang.
Since I was here anyway I also removed the obsolete -O3 since this is the default anyway for optimized builds.
Needed to remove the obsolete fopenmp-simd flag that also doesn't work on clang.
Since I was here anyway I also removed the obsolete -O3 since this is the default anyway for optimized builds.