Fix float128 uses of xlocale.h [committed]

[Gabriel F. T. Gomes]

On Thu, 22 Jun 2017 22:35:25 +0000
Joseph Myers <joseph@codesourcery.com> wrote:

> Three float128 files still include xlocale.h after it was removed.  I
> don't know why this didn't cause problems for powerpc64le float128
> testing; it did cause problems for my x86_64 float128 testing.  This
> patch changes the includes to use bits/types/locale_t.h.

It caused problems for powerpc64le testing, indeed.  But, my rebasing was
a little outdated.  Thanks for doing this.