re PR target/30652 (SSE expansion is missing for isinf() and other fpclassify functions)

re PR target/30652 (SSE expansion is missing for isinf() and other fpclassify functions)

	PR target/30652

	* builtins.c (expand_builtin_interclass_mathfn): Allow for missing
	optabs infrastructure.  Provide generic implementation for
	FINITE/ISFINITE.
	(expand_builtin): Handle FINITE/ISFINITE.
	(fold_builtin_classify): Make ISFINITE canonical instead of FINITE.
	(fold_builtin_1): Likewise.

	* builtins.def (BUILT_IN_ISFINITE): New.

	* doc/extend.texi: Document isfinite.

testsuite:
	* gcc.dg/pr28796-1.c: Add more cases.
	* gcc.dg/pr28796-2.c: Likewise.

From-SVN: r126725