[PR libgfortran/78449] XFAIL ieee_8.f90 on aarch64 and arm

ARM and AArch64 may not support trapping so runtime and
compile time check can differ.

gcc/testsuite/
	PR libgfortran/78449 
	* gfortran.dg/ieee/ieee_8.f90 (aarch64*gnu, arm*gnu*): Mark xfail.

From-SVN: r242688

gcc/testsuite/ChangeLog

+2016-11-22  Szabolcs Nagy  <szabolcs.nagy@arm.com>
+
+	PR libgfortran/78449 
+	* gfortran.dg/ieee/ieee_8.f90 (aarch64*gnu, arm*gnu*): Mark xfail.
+
 2016-11-21  Jeff Law  <law@redhat.com>
 
         PR target/68538

gcc/testsuite/gfortran.dg/ieee/ieee_8.f90

-! { dg-do run }
+! { dg-do run { xfail aarch64*-*-gnu arm*-*-gnueabi arm*-*-gnueabihf } }
+! XFAIL because of PR libfortran/78449.
 
 module foo
   use :: ieee_exceptions