Bug #47141 "mysqltest" breaks because it tries to act on a debug option which is disabled

Replace --debug with --loose-debug to prevent failure exit
Update: added workaround for 50627, skip all debugging of mysqlbinlog

mysql-test/mysql-test-run.pl

@@ -1783,9 +1783,12 @@ sub executable_setup () {
 sub client_debug_arg($$) {
   my ($args, $client_name)= @_;
 
+  # Workaround for Bug #50627: drop any debug opt
+  return if $client_name =~ /^mysqlbinlog/;
+
   if ( $opt_debug ) {
     mtr_add_arg($args,
-		"--debug=d:t:A,%s/log/%s.trace",
+		"--loose-debug=d:t:A,%s/log/%s.trace",
 		$path_vardir_trace, $client_name)
   }
 }