re PR fortran/19310 ([4.1 Only] unnecessary error for overflowing results)

re PR fortran/19310 ([4.1 Only] unnecessary error for overflowing results)

2006-06-18  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/19310
	* arith.c (gfc_range_check): Return ARITH_OK if -fno-range-check. Add
	return of ARITH_NAN, ARITH_UNDERFLOW, and ARITH_OVERFLOW.
	(gfc_arith_divide): If -fno-range-check allow mpfr to divide by zero.
	* gfortran.h (gfc_option_t): Add new flag.
	* invoke.texi: Document new flag.
	* lang.opt: Add option -frange-check.
	* options.c (gfc_init_options): Initialize new flag.
	(gfc_handle_options): Set flag if invoked.
	* simplify.c (range_check): Add error messages for
	overflow, underflow, and other errors.
	* trans-const.c (gfc_conv_mpfr_to_tree): Build NaN and Inf from mpfr
	result.

From-SVN: r114752