[arm] Fix gcc.target/arm/g2.c and scd42-2.c for --with-mode=thumb hardfloat targets

These -mcpu=xscale tests are ARM-only tests and they go to great pains to reject
explicit overriding options, but they're missing the -marm in their dg-options, which means
they will still give that nasty Thumb1 hard-float error when testing an implicit --with-mode=thumb
toolchain (--with-cpu=cortex-a15 --with-fpu=neon-vfpv4 --with-float=hard --with-mode=thumb, for example).

This patch adds the missing -marm and all is good again.

     * gcc.target/arm/g2.c: Add -marm to dg-options.
     * gcc.target/arm/scd42-2.c: Likewise.

From-SVN: r256812

gcc/testsuite/ChangeLog

+2018-01-17  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* gcc.target/arm/g2.c: Add -marm to dg-options.
+	* gcc.target/arm/scd42-2.c: Likewise.
+
 2018-01-17  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/83287

gcc/testsuite/gcc.target/arm/g2.c

 /* Verify that hardware multiply is preferred on XScale. */
 /* { dg-do compile } */
-/* { dg-options "-mcpu=xscale -O2" } */
+/* { dg-options "-mcpu=xscale -O2 -marm" } */
 /* { dg-skip-if "Test is specific to the Xscale" { arm*-*-* } { "-march=*" } { "-march=xscale" } } */
 /* { dg-skip-if "Test is specific to the Xscale" { arm*-*-* } { "-mcpu=*" } { "-mcpu=xscale" } } */
 /* { dg-skip-if "Test is specific to ARM mode" { arm*-*-* } { "-mthumb" } { "" } } */

gcc/testsuite/gcc.target/arm/scd42-2.c

@@ -4,7 +4,7 @@
 /* { dg-skip-if "Test is specific to the Xscale" { arm*-*-* } { "-mcpu=*" } { "-mcpu=xscale" } } */
 /* { dg-skip-if "Test is specific to ARM mode" { arm*-*-* } { "-mthumb" } { "" } } */
 /* { dg-require-effective-target arm32 } */
-/* { dg-options "-mcpu=xscale -O" } */
+/* { dg-options "-mcpu=xscale -O -marm" } */
 
 unsigned load2(void) __attribute__ ((naked));
 unsigned load2(void)