aarch64: Disable shrink-wrap for locally-streaming functions [PR 123624]

aarch64: Disable shrink-wrap for locally-streaming functions [PR 123624]

The meaning of poly_int values changes depending on whether we are in
streaming or non-streaming mode, but this dependency is not explicitly
tracked.  Locally-streaming functions can change streaming state in the
prologue and epilogue, so it is unsafe to apply shrink wrapping to these
functions, as doing so could change the mode seen by instructions like
cntd.

gcc/ChangeLog:

	PR target/123624
	* config/aarch64/aarch64-protos.h
	(aarch64_use_simple_return_insn_p): New.
	* config/aarch64/aarch64.cc
	(aarch64_use_simple_return_insn_p): New, used...
	* config/aarch64/aarch64.md (simple_return): ...here.

gcc/testsuite/ChangeLog:

	PR target/123624
	* gcc.target/aarch64/sme/sme-shrinkwrap.c: New test.