Report usermode gdb exit codes

diff -u -p -r1.25 gdbstub.c
@@ -656,6 +656,22 @@ gdb_handlesig (CPUState *env, int sig)
   }
   return sig;
 }
+
+/* Tell the remote gdb that the process has exited.  */
+void gdb_exit(CPUState *env, int code)
+{
+  GDBState *s;
+  char buf[4];
+
+  if (gdbserver_fd < 0)
+    return;
+
+  s = &gdbserver_state;
+
+  snprintf(buf, sizeof(buf), "W%02x", code);
+  put_packet(s, buf);
+}
+
 #else
 static int gdb_can_read(void *opaque)
 {

diff -u -p -r1.1 gdbstub.h
@@ -5,6 +5,7 @@
 
 #ifdef CONFIG_USER_ONLY
 int gdb_handlesig (CPUState *, int);
+void gdb_exit(CPUState *, int);
 #endif
 int gdbserver_start(int);
 

diff -u -p -r1.59 syscall.c
@@ -1603,6 +1603,7 @@ long do_syscall(void *cpu_env, int num, 
 #ifdef HAVE_GPROF
         _mcleanup();
 #endif
+        gdb_exit(cpu_env, arg1);
         /* XXX: should free thread stack and CPU env */
         _exit(arg1);
         ret = 0; /* avoid warning */

@@ -2409,6 +2410,7 @@ long do_syscall(void *cpu_env, int num, 
 #ifdef __NR_exit_group
         /* new thread calls */
     case TARGET_NR_exit_group:
+        gdb_exit(cpu_env, arg1);
         ret = get_errno(exit_group(arg1));
         break;
 #endif