fold-const.c (fold_mathfn_compare): New function to simplify comparisons against built-in math functions.


	* fold-const.c (fold_mathfn_compare): New function to simplify
	comparisons against built-in math functions.  Fold comparisons
	of sqrt against constants.
	(fold): Call fold_mathfn_compare when appropriate.

	* gcc.dg/builtins-6.c: New test case.

From-SVN: r64619