builtins.def (DEF_FLOATN_BUILTIN): Change most _Float<N> and _Float<N>X built-in functions so that the variant...

2017-10-31  Michael Meissner  <meissner@linux.vnet.ibm.com>

	* builtins.def (DEF_FLOATN_BUILTIN): Change most _Float<N> and
	_Float<N>X built-in functions so that the variant without the
	"__builtin_" prefix is only enabled for the GNU C and Objective C
	languages when they are in non-strict ANSI/ISO mode.
	(DEF_EXT_LIB_FLOATN_NX_BUILTINS): Likewise.
	* target.def (floatn_builtin_p): Add a target hook to control
	whether _Float<N> and _Float<N>X built-in functions without the
	"__builtin_" prefix are enabled, and return true for C and
	Objective C in the default hook.  Include langhooks.h in
	targhooks.c.
	* targhooks.h (default_floatn_builtin_p): Likewise.
	* targhooks.c (default_floatn_builtin_p): Likewise.
	* doc/tm.texi.in (TARGET_FLOATN_BUILTIN_P): Document the
	floatn_builtin_p target hook.
	* doc/tm.texi (TARGET_FLOATN_BUILTIN_P): Likewise.

From-SVN: r254277