re PR fortran/38718 (some simplifiers for elemental intrinsics missing; required for init expressions)

	PR fortran/38718

	* intrinsic.c (add_functions): Add simplifiers for ISNAN,
	IS_IOSTAT_END and IS_IOSTAT_EOR.
	* intrinsic.h (gfc_simplify_is_iostat_end,
	* gfc_simplify_is_iostat_eor,
	gfc_simplify_isnan): New prototypes.
	* intrinsic.c (gfc_simplify_is_iostat_end,
	* gfc_simplify_is_iostat_eor,
	gfc_simplify_isnan): New functions.

	* gfortran.dg/is_iostat_end_eor_2.f90: New test.
	* gfortran.dg/nan_5.f90: New test.

From-SVN: r148367