arm: Avoid emitting bogus CFA adjusts for CMSE nonsecure calls [PR99725]

arm: Avoid emitting bogus CFA adjusts for CMSE nonsecure calls [PR99725]

The PR shows us attaching REG_CFA_ADJUST_CFA notes to stack pointer
adjustments emitted in cmse_nonsecure_call_inline_register_clear (when
-march=armv8.1-m.main). However, the stack pointer is not guaranteed to
be the CFA reg. If we're at -O0 or we have -fno-omit-frame-pointer, then
the frame pointer will be used as the CFA reg, and these notes on the sp
adjustments will lead to ICEs in dwarf2out_frame_debug_adjust_cfa.

This patch avoids emitting these notes if the current function has a
frame pointer.

gcc/ChangeLog:

	PR target/99725
	* config/arm/arm.c (cmse_nonsecure_call_inline_register_clear):
	Avoid emitting CFA adjusts on the sp if we have the fp.

gcc/testsuite/ChangeLog:

	PR target/99725
	* gcc.target/arm/cmse/pr99725.c: New test.