configure.host (ieee_flags): Add -mieee for alpha*.

libgfortran/ChangeLog:

	* configure.host (ieee_flags): Add -mieee for alpha*.

	* config/fpu-glibc.h (support_fpu_rounding_mode): Correctly handle
	GFC_FPE_UPWARD, GFC_FPE_DOWNWARD and GFC_FPE_TOWARDZERO.
	* config/fpu-aix.h (support_fpu_rounding_mode): Ditto.

testsuite/ChangeLog:

	* gfortran.dg/ieee/ieee_1.F90 (dg-additional-options): Remove -O0.
	* gfortran.dg/ieee/ieee_rounding_1.f90 (dg-additional-options): Add.

From-SVN: r212224