[testsuite][arm] Fix cmse-15.c expected output

The cmse-15.c testcase fails at -Os because ICF means that we
generate
nonsecure2:
        b       nonsecure0

which is OK, but does not match the currently expected
nonsecure2:
...
        bl      __gnu_cmse_nonsecure_call

(see https://gcc.gnu.org/pipermail/gcc-patches/2020-April/543190.html)

The test has already different expectations for v8-M and v8.1-M.

This patch uses check-function-bodies to account for the
different possibilities:
- v8-M vs v8.1-M via different target selectors where needed
- code generation variants (-0?) via multiple regexps

I've tested that the test now passes with --target-board=-march=armv8-m.main
and --target-board=-march=armv8.1-m.main.

gcc/testsuite/ChangeLog

 2020-04-09  Christophe Lyon  <christophe.lyon@linaro.org>
 
+	* gcc.target/arm/cmse/cmse-15.c: Use check-function-bodies.
+
+2020-04-09  Christophe Lyon  <christophe.lyon@linaro.org>
+
 	* lib/scanasm.exp (check-function-bodies): Use non-greedy regexp
 	when extracting the target selector.
 

gcc/testsuite/gcc.target/arm/cmse/cmse-15.c

 /* { dg-do compile } */
 /* { dg-options "-mcmse" } */
+/* ARMv8-M expectation with target { ! arm_cmse_clear_ok }.  */
+/* ARMv8.1-M expectation with target arm_cmse_clear_ok.  */
+/* { dg-final { check-function-bodies "**" "" "" } } */
 
 int __attribute__ ((cmse_nonsecure_call)) (*ns_foo) (void);
 int (*s_bar) (void);
@@ -11,67 +14,204 @@ typedef int s_bar_t (void);
 typedef int __attribute__ ((cmse_nonsecure_call)) (* ns_foo_ptr) (void);
 typedef int (*s_bar_ptr) (void);
 
+/*
+** nonsecure0:  { target arm_cmse_clear_ok }
+**	...
+**	blxns	r[0-3]
+**	...
+*/
+/*
+** nonsecure0: { target { ! arm_cmse_clear_ok } }
+**	...
+**	bl	__gnu_cmse_nonsecure_call
+**	...
+*/
 int nonsecure0 (ns_foo_t * ns_foo_p)
 {
   return ns_foo_p ();
 }
 
+/*
+** nonsecure1:  { target arm_cmse_clear_ok }
+**	...
+**	blxns	r[0-3]
+**	...
+*/
+/*
+** nonsecure1: { target { ! arm_cmse_clear_ok } }
+**	...
+**	bl	__gnu_cmse_nonsecure_call
+**	...
+*/
 int nonsecure1 (ns_foo_t ** ns_foo_p)
 {
   return (*ns_foo_p) ();
 }
 
+/*
+** nonsecure2:  { target arm_cmse_clear_ok }
+**	...
+** (
+**	blxns	r[0-3]
+** |
+**	b	nonsecure0
+** )
+**	...
+*/
+/*
+** nonsecure2: { target { ! arm_cmse_clear_ok } }
+**	...
+** (
+**	bl	__gnu_cmse_nonsecure_call
+** |
+**	b	nonsecure0
+** )
+**	...
+*/
 int nonsecure2 (ns_foo_ptr ns_foo_p)
 {
   return ns_foo_p ();
 }
+
+/*
+** nonsecure3:  { target arm_cmse_clear_ok }
+**	...
+**	blxns	r[0-3]
+**	...
+*/
+/*
+** nonsecure3: { target { ! arm_cmse_clear_ok } }
+**	...
+**	bl	__gnu_cmse_nonsecure_call
+**	...
+*/
 int nonsecure3 (ns_foo_ptr * ns_foo_p)
 {
   return (*ns_foo_p) ();
 }
 
+/*
+** secure0:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** )
+**	...
+*/
 int secure0 (s_bar_t * s_bar_p)
 {
   return s_bar_p ();
 }
 
+/*
+** secure1:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** )
+**	...
+*/
 int secure1 (s_bar_t ** s_bar_p)
 {
   return (*s_bar_p) ();
 }
 
+/*
+** secure2:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** |
+**	b	secure0
+** )
+**	...
+*/
 int secure2 (s_bar_ptr s_bar_p)
 {
   return s_bar_p ();
 }
 
+/*
+** secure3:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** )
+**	...
+*/
 int secure3 (s_bar_ptr * s_bar_p)
 {
   return (*s_bar_p) ();
 }
 
+/*
+** nonsecure4:  { target arm_cmse_clear_ok }
+**	...
+**	blxns	r[0-3]
+**	...
+*/
+/*
+** nonsecure4: { target { ! arm_cmse_clear_ok } }
+**	...
+**	bl	__gnu_cmse_nonsecure_call
+**	...
+*/
 int nonsecure4 (void)
 {
   return ns_foo ();
 }
 
+/*
+** nonsecure5:  { target arm_cmse_clear_ok }
+**	...
+**	blxns	r[0-3]
+**	...
+*/
+/*
+** nonsecure5: { target { ! arm_cmse_clear_ok } }
+**	...
+**	bl	__gnu_cmse_nonsecure_call
+**	...
+*/
 int nonsecure5 (void)
 {
   return (*ns_foo2) ();
 }
 
+/*
+** secure4:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** )
+**	...
+*/
 int secure4 (void)
 {
   return s_bar ();
 }
 
+/*
+** secure5:
+**	...
+** (
+**	bx	r[0-3]
+** |
+**	blx	r[0-3]
+** )
+**	...
+*/
 int secure5 (void)
 {
   return (*s_bar2) ();
 }
-
-/* ARMv8-M expectation.  */
-/* { dg-final { scan-assembler-times "bl\\s+__gnu_cmse_nonsecure_call" 6 { target { ! arm_cmse_clear_ok } } } } */
-
-/* ARMv8.1-M expectation.  */
-/* { dg-final { scan-assembler-times "blxns" 6 { target arm_cmse_clear_ok } } } */