[Bug target/114484] #include <xmmintrin.h> changes ::abs in std::abs

["vincenzo.innocente at cern dot ch" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114484

--- Comment #9 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
We observe that including xmmintrin.h the behaviour of some code,
notably abs(x), when x is float or double changes.
And this depends on the platform as  xmmintrin.h is x86_64 specific.
Yes, is 20 years that is like that and people always wandered why abs(x) was
behaving differently in different parts of the code and now asking why it
behaves differently on x86_64 and ARM.
The workaround is obvious: use std::abs.

I personally find very unconfortable that including (even through cascade)
xmmintrin.h changes the behaviour of "abs(x)" 


If everybody on GCC side is confortable with this situation we will just take
note and try to be more strict with code visual inspection.