-mno-long-calls for expected regalloc in arm/fp16-aapcs-2.c test

The implicit -mlong-calls used in our arm-vxworks configurations
changes the register allocation patterns in the arm/fp16-aapcs-2.c
test: r3 ends up used in the long-call sequence, and we end up using
ip as a temporary, which doesn't match the expected mov patterns.

This patch adds an explicit -mno-long-calls for the generated code to
match the expectation.


for  gcc/testsuite/ChangeLog

	* gcc.target/arm/fp16-aapcs-2.c: Use -mno-long-calls.

gcc/testsuite/gcc.target/arm/fp16-aapcs-2.c

@@ -1,6 +1,6 @@
 /* { dg-do compile }  */
 /* { dg-require-effective-target arm_fp16_ok } */
-/* { dg-options "-mfloat-abi=softfp -O2" }  */
+/* { dg-options "-mfloat-abi=softfp -O2 -mno-long-calls" }  */
 /* { dg-add-options arm_fp16_ieee } */
 /* { dg-skip-if "incompatible float-abi" { arm*-*-* } { "-mfloat-abi=hard" } } */