sigsegv: Port to CHERI

[Bruno Haible]

The patch below fixes the following test failures:

FAIL: test-c-stack.sh
FAIL: test-c-stack2.sh
FAIL: test-sigsegv-catch-segv1
FAIL: test-sigsegv-catch-segv2
FAIL: test-sigsegv-catch-stackoverflow1
FAIL: test-sigsegv-catch-stackoverflow2


2023-11-09  Bruno Haible  <br...@clisp.org>

        sigsegv: Port to CHERI.
        * lib/sigsegv.c: Treat __aarch64__ like __arm64__.
        (SIGSEGV_FOR_ALL_SIGNALS): Treat SIGPROT like SIGSEGV and SIGBUS.

diff --git a/lib/sigsegv.c b/lib/sigsegv.c
index 8263d9b7bd..5f9bc08bb9 100644
--- a/lib/sigsegv.c
+++ b/lib/sigsegv.c
@@ -430,7 +430,7 @@ int libsigsegv_version = LIBSIGSEGV_VERSION;
 
 #if defined __FreeBSD_kernel__ || defined __FreeBSD__ || defined __DragonFly__ 
/* GNU/kFreeBSD, FreeBSD */
 
-# if defined __arm__ || defined __armhf__ || defined __arm64__
+# if defined __arm__ || defined __armhf__ || (defined __arm64__ || defined 
__aarch64__)
 
 #  define SIGSEGV_FAULT_HANDLER_ARGLIST  int sig, siginfo_t *sip, void *ucp
 #  define SIGSEGV_FAULT_ADDRESS  sip->si_addr
@@ -825,8 +825,20 @@ int libsigsegv_version = LIBSIGSEGV_VERSION;
     || defined __FreeBSD_kernel__ || defined __FreeBSD__ || defined 
__DragonFly__ \
     || defined __NetBSD__ || defined __OpenBSD__ \
     || (defined __APPLE__ && defined __MACH__)
-# define SIGSEGV_FOR_ALL_SIGNALS(var,body) \
-    { int var; var = SIGSEGV; { body } var = SIGBUS; { body } }
+# if defined __CHERI__
+#  define SIGSEGV_FOR_ALL_SIGNALS(var,body) \
+     { int var;                             \
+       var = SIGSEGV; { body }              \
+       var = SIGBUS; { body }               \
+       var = SIGPROT; { body }              \
+     }
+# else
+#  define SIGSEGV_FOR_ALL_SIGNALS(var,body) \
+     { int var;                             \
+       var = SIGSEGV; { body }              \
+       var = SIGBUS; { body }               \
+     }
+# endif
 #else
 # define SIGSEGV_FOR_ALL_SIGNALS(var,body) \
     { int var; var = SIGSEGV; { body } }