[PATCH] Fix compile error due to [[noreturn]] with clang

[andrew@andrewoates.com]

From: Andrew Oates <andrew@andrewoates.com>

Since commit d9deb60b2e9e94b532f43a7d3ddddf5ddf6dbdd3, I get the
following compiler error when building binutils (cross-compiling) on
macos:

 CXX    remote-sim.o
../../gdb/remote-sim.c:334:28: error: assigning to 'void (*)(host_callback *, const char *, ...) __attribute__((noreturn))' (aka 'void (*)(host_callback_struct *, const char *, ...) __attribute__((noreturn))') from incompatible type 'void (host_callback
*, const char *, ...)' (aka 'void (host_callback_struct *, const char *, ...)')
      gdb_callback.error = gdb_os_error;
                           ^~~~~~~~~~~~
1 error generated.

This appears to be due to the mismatch between ATTRIBUTE_NORETURN and
[[noreturn]] on gdb_os_error.  Removing ATTTRIBUTE_NORETURN on the
declaration of host_callback::error resolves the issue.

Tested by compiling on macos both with the system clang, as well as with
GCC 14.  With clang, remote-sim.c does not compile (per above) without
this patch.  With GCC, it compiles with and without the patch (it
doesn't link, but AFAICT that is unrelated).
---
 include/sim/callback.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/sim/callback.h b/include/sim/callback.h
index f69f783abac..045ac3411af 100644
--- a/include/sim/callback.h
+++ b/include/sim/callback.h
@@ -129,7 +129,7 @@ struct host_callback_struct
      In the case of gdb "exiting" means doing a longjmp back to the main
      command loop.  */
   void (*error) (host_callback *, const char *, ...)
-    ATTRIBUTE_NORETURN ATTRIBUTE_PRINTF_2;
+    ATTRIBUTE_PRINTF_2;
 
   int last_errno;		/* host format */
 
-- 
2.46.0