linux-user: Handle BUS_ADRALN in host_signal_handler

Handle BUS_ADRALN via cpu_loop_exit_sigbus, but allow other SIGBUS
si_codes to continue into the host-to-guest signal conversion code.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

linux-user/signal.c

@@ -860,6 +860,9 @@ static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
             cpu_loop_exit_sigsegv(cpu, guest_addr, access_type, maperr, pc);
         } else {
             sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
+            if (info->si_code == BUS_ADRALN) {
+                cpu_loop_exit_sigbus(cpu, guest_addr, access_type, pc);
+            }
         }
 
         sync_sig = true;