[PATCH][RFH] (3/3) Vectorize some builtins on x86_64 by using libgcc-math

[Paolo Bonzini]

>> I think the solution is just to put these tests in libgcc-math.dg/vect, though
>> somebody else's opinion may be more valuable than mine.
>>     
>
> It affects all tests that use -ftree-vectorize (which at the moment,
> maybe wrongly so, causes us to link against libgcc-math).  I'm open to
> suggestions, but if you mean moving all vect testcases to the libgcc-math
> testsuite that doesn't sound right.  Or wasn't this what you suggested?
>   

I missed that all vectorized programs link against libgcc-math.  I don't 
know if this is okay...  this definitely looks like a series of patches 
that should be reviewed by a GWP...

Paolo