arm: Zero/Sign extends for CMSE security on Armv8-M.baseline [PR115253]

arm: Zero/Sign extends for CMSE security on Armv8-M.baseline [PR115253]

Properly handle zero and sign extension for Armv8-M.baseline as
Cortex-M23 can have the security extension active.
Currently, there is an internal compiler error on Cortex-M23 for the
epilog processing of sign extension.

This patch addresses the following CVE-2024-0151 for Armv8-M.baseline.

gcc/ChangeLog:

	PR target/115253
	* config/arm/arm.cc (cmse_nonsecure_call_inline_register_clear):
	Sign extend for Thumb1.
	(thumb1_expand_prologue): Add zero/sign extend.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>
Co-authored-by: Yvan ROUX <yvan.roux@foss.st.com>