Sync config and libiberty with GCC

Sync config and libiberty with GCC

config/

2020-04-29  H.J. Lu  <hongjiu.lu@intel.com>

	Sync with GCC
	2020-04-28  H.J. Lu  <hongjiu.lu@intel.com>

	PR bootstrap/94739
	* cet.m4 (GCC_CET_HOST_FLAGS): Add -fcf-protection=none to
	-Wl,-z,ibt,-z,shstk.  Check whether -fcf-protection=none
	-Wl,-z,ibt,-z,shstk works first.

	2020-04-25  H.J. Lu  <hongjiu.lu@intel.com>

	PR bootstrap/94739
	* cet.m4 (GCC_CET_HOST_FLAGS): New.

	2020-04-22  Jakub Jelinek  <jakub@redhat.com>

	PR libfortran/94694
	PR libfortran/94586
	* math.m4 (GCC_CHECK_MATH_INLINE_BUILTIN_FALLBACK1,
	GCC_CHECK_MATH_INLINE_BUILTIN_FALLBACK2): New.

libiberty/

2020-04-28  H.J. Lu  <hongjiu.lu@intel.com>

	PR bootstrap/94739
	* configure: Regenerated.