[patch, testsuite, arm] Fix ICE in gcc.dg/gimplefe-28.c

[Sandra Loosemore]

For the default multilib on arm-none-eabi, gcc.dg/gimplefe-28 has been 
getting an ICE because, while the target-supports infrastructure is 
probing to see if it can add the command-line options to enable the sqrt 
insn ("-mfpu=vfp -mfloat-abi=softfp"), it is not actually adding those 
options when building this testcase.  :-S  The hook to do this is 
already there; it just needs a case for arm.

OK to commit?
-Sandra
2019-09-13  Sandra Loosemore  <san...@codesourcery.com>

	gcc/testsuite/
	* lib/target-supports.exp (add_options_for_sqrt_insn): Add
	arm options consistent with check_effective_target_arm_vfp_ok.
Index: gcc/testsuite/lib/target-supports.exp
===================================================================
--- gcc/testsuite/lib/target-supports.exp	(revision 275699)
+++ gcc/testsuite/lib/target-supports.exp	(working copy)
@@ -6670,6 +6670,9 @@ proc add_options_for_sqrt_insn { flags }
     if { [istarget amdgcn*-*-*] } {
 	return "$flags -ffast-math"
     }
+    if { [istarget arm*-*-*] } {
+	return "$flags -mfpu=vfp -mfloat-abi=softfp"
+    }
     return $flags
 }