Fix float128 uses of xlocale.h.

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.

Tested for x86_64 (in conjunction with float128 patches).

	* sysdeps/ieee754/float128/strtof128_l.c: Include
	<bits/types/locale_t.h> instead of <xlocale.h>.
	* sysdeps/ieee754/float128/wcstof128.c: Likewise.
	* sysdeps/ieee754/float128/wcstof128_l.c: Likewise.

ChangeLog

@@ -1,3 +1,10 @@
+2017-06-22  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/ieee754/float128/strtof128_l.c: Include
+	<bits/types/locale_t.h> instead of <xlocale.h>.
+	* sysdeps/ieee754/float128/wcstof128.c: Likewise.
+	* sysdeps/ieee754/float128/wcstof128_l.c: Likewise.
+
 2017-06-22  Siddhesh Poyarekar  <siddhesh@sourceware.org>
 
 	* benchtests/scripts/benchout_strings.schema.json: New file.

sysdeps/ieee754/float128/strtof128_l.c

@@ -16,7 +16,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#include <xlocale.h>
+#include <bits/types/locale_t.h>
 
 /* Bring in potential typedef for _Float128 early for declaration below.  */
 #include <bits/floatn.h>

sysdeps/ieee754/float128/wcstof128.c

@@ -17,7 +17,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stddef.h>
-#include <xlocale.h>
+#include <bits/types/locale_t.h>
 
 #define	USE_WIDE_CHAR	1
 

sysdeps/ieee754/float128/wcstof128_l.c

@@ -17,7 +17,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <stddef.h>
-#include <xlocale.h>
+#include <bits/types/locale_t.h>
 
 
 #define	USE_WIDE_CHAR	1