PR fortran/33197

	* intrinsic.c (add_functions): Use ERFC_SCALED simplification.
	* intrinsic.h (gfc_simplify_erfc_scaled): New prototype.
	* simplify.c (fullprec_erfc_scaled, asympt_erfc_scaled,
	gfc_simplify_erfc_scaled): New functions.

	* gfortran.dg/erf_2.F90: New test.
	* gfortran.dg/erfc_scaled_2.f90: New test.

From-SVN: r147621