Move float128 inlines from sysdeps/generic/math_private.h to include/math.h.

Continuing the cleanup of math_private.h, with a view to it becoming
the header for the APIs defined therein and not also a header with
inline variants of math.h APIs, this patch moves inline definitions of
__isinff128 and fabsf128 to include/math.h, so that any users of
math.h in glibc automatically get the optimized functions rather than
quietly missing them if they do not also include math_private.h.

Tested for x86_64 and x86, and with build-many-glibcs.py with GCC 6.
There are changes to installed stripped libc.so on configurations with
distinct _Float128, because of __printf_fp_l code that now gets the
__isinff128 inline where previously it called the out-of-line
function because of the lack of a math_private.h call.  It seems
appropriate that this code does get the inline (as it would
automatically with GCC 7 and later when the built-in function is used)
rather than being the only place in glibc that does not.

	* sysdeps/generic/math_private.h
	[__HAVE_DISTINCT_FLOAT128 && !__GNUC_PREREQ (7, 0)] (__isinff128):
	Move this inline function ....
	[__HAVE_DISTINCT_FLOAT128] (fabsf128): And this one ....
	* include/math.h [!_ISOMAC]: To here....

1 files changed, 8 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 70ebfce..4fd46f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-09-05  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/generic/math_private.h
+	[__HAVE_DISTINCT_FLOAT128 && !__GNUC_PREREQ (7, 0)] (__isinff128):
+	Move this inline function ....
+	[__HAVE_DISTINCT_FLOAT128] (fabsf128): And this one ....
+	* include/math.h [!_ISOMAC]: To here....
+
 2018-09-04  Joseph Myers  <joseph@codesourcery.com>
 
 	* sysdeps/generic/fenv_private.h [FE_ALL_EXCEPT == 0]: Move this