Expand the SIGSEGV handler to also cover SIGBUS

bin/varnishd/mgt/mgt_child.c

@@ -377,6 +377,7 @@ mgt_launch_child(struct cli *cli)
 			sa.sa_sigaction = child_sigsegv_handler;
 			sa.sa_flags = SA_SIGINFO;
 			(void)sigaction(SIGSEGV, &sa, NULL);
+			(void)sigaction(SIGBUS, &sa, NULL);
 		}
 		(void)signal(SIGINT, SIG_DFL);
 		(void)signal(SIGTERM, SIG_DFL);

bin/varnishd/mgt/mgt_param_tbl.c

@@ -505,7 +505,7 @@ struct parspec mgt_parspec[] = {
 	{ "sigsegv_handler", tweak_bool, &mgt_param.sigsegv_handler,
 		NULL, NULL,
 		"Install a signal handler which tries to dump debug "
-		"information on segmentation faults.",
+		"information on segmentation and buserror faults.",
 		MUST_RESTART,
 		"off", "bool" },
 	{ "vcl_dir", tweak_string, &mgt_vcl_dir,