arch: arm: cortex_m: add memory to the clobber list

Add "memory" to the clobber list"

From GCC 14 the compiler optimizes away memory accesses that do not
impact the asm block. Adding the memory to the clobber list lets the
compiler know that the memory state is to be preserved.

(cherry picked from commit 63890e2)

Original-Signed-off-by: Wilfried Chauveau <wilfried.chauveau@arm.com>
Original-Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
GitOrigin-RevId: 63890e2
Cr-Build-Id: 8732025046822077009
Cr-Build-Url: https://cr-buildbucket.appspot.com/build/8732025046822077009
Copybot-Job-Name: zephyr-main-copybot-downstream
Change-Id: I0dba2b4ef9c3cd32ff33a6c5f808b3ca73c689d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/+/5998443
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Reviewed-by: Jeremy Bettis <jbettis@chromium.org>
Commit-Queue: Jeremy Bettis <jbettis@chromium.org>

arch/arm/core/cortex_m/thread.c

@@ -588,7 +588,7 @@ void arch_switch_to_main_thread(struct k_thread *main_thread, char *stack_ptr,
 	"bx    r4\n"		/* We don’t intend to return, so there is no need to link. */
 	:
 	: "r" (_main), "r" (stack_ptr)
-	: "r0", "r1", "r2", "r3", "r4", "ip", "lr");
+	: "r0", "r1", "r2", "r3", "r4", "ip", "lr", "memory");
 
 	CODE_UNREACHABLE;
 }