* builtins.c (fold_fixed_mathfn): New function.
	(fold_builtin_lround, fold_builtin): Use it.

testsuite:
	* gcc.dg/torture/builtin-integral-1.c: Reorg and add more cases.
	* gcc.dg/torture/builtin-convert-3.c: New test.

From-SVN: r81403