Use dg-additional-options instead of dg-options

Use dg-additional-options rather than dg-options to avoid overwriting the
default IEEE options which are passed by ieee.exp and necessary.

	PR testsuite/88639
	* gfortran.dg/ieee/ieee_10.f90: Use dg-additional-options
	instead of dg-options.

From-SVN: r267478

gcc/testsuite/ChangeLog

+2018-12-30  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR testsuite/88639
+	* gfortran.dg/ieee/ieee_10.f90: Use dg-additional-options
+	instead of dg-options.
+
 2018-12-29  Dominique d'Humieres  <dominiq@gcc.gnu.org>
 
 	* g++.dg/abi/key2.C: Silence the [-Wreturn-type] warning.

gcc/testsuite/gfortran.dg/ieee/ieee_10.f90

 ! { dg-do run }
-! { dg-options "-ffpe-trap=overflow,invalid" }
+! { dg-additional-options "-ffpe-trap=overflow,invalid" }
+!
+! Use dg-additional-options rather than dg-options to avoid overwriting the
+! default IEEE options which are passed by ieee.exp and necessary.
 program foo
 
    use ieee_arithmetic