re PR target/71241 ([x86] Missing built-in functions for float128 NaNs)

re PR target/71241 ([x86] Missing built-in functions for float128 NaNs)

	PR target/71241
	* config/i386/i386.i386-builtin-types.def (CONST_STRING):
	New primitive type.
	(FLOAT128_FTYPE_CONST_STRING): New function type.
	* config/i386/i386.c (enum ix86_builtins) [IX86_BUILTIN_NANQ]: New.
	[IX86_BUILTIN_NANSQ]: Ditto.
	(ix86_fold_builtin): Handle IX86_BUILTIN_NANQ and IX86_BUILTIN_NANSQ.
	(ix86_init_builtin_types) Declare const_string_type_node.
	Add __builtin_nanq and __builtin_nansq builtin functions.
	(ix86_expand_builtin): Handle IX86_BUILTIN_NANQ and IX86_BUILTIN_NANSQ.
	* doc/extend.texi (x86 Built-in Functions): Document
	__builtin_nanq and __builtin_nansq.

testsuite/ChangeLog:

	PR target/71241
	* testsuite/gcc.dg/torture/float128-nan.c: New test.

From-SVN: r237338