Post-push for MDEV-13437

A new $MYSQLD_LAST_CMD evaluation was too late in case --manual-gdb.
Now it is done before the server restart type branches which is safe
and the args value has been fully computed by the new point of
evaluation.

mysql-test/mysql-test-run.pl

@@ -5477,6 +5477,11 @@ sub mysqld_start ($$) {
     }
   }
 
+  # "Dynamic" version of MYSQLD_CMD is reevaluated with each mysqld_start.
+  # Use it to restart the server at testing a failing server start (e.g
+  # due to incompatible options).
+  $ENV{'MYSQLD_LAST_CMD'}= "$exe  @$args";
+
   if ( $opt_gdb || $opt_manual_gdb )
   {
     gdb_arguments(\$args, \$exe, $mysqld->name());
@@ -5573,11 +5578,6 @@ sub mysqld_start ($$) {
   # Remember options used when starting
   $mysqld->{'started_opts'}= $extra_opts;
 
-  # "Dynamic" version of MYSQLD_CMD is reevaluated with each mysqld_start.
-  # Use it to restart the server at testing a failing server start (e.g
-  # due to incompatible options).
-  $ENV{'MYSQLD_LAST_CMD'}= "$exe  @$args";
-
   return;
 }