PS-5363 (Merge MySQL 8.0.17): fixed regexps in the rpl.rpl_perfschema…

…_threads_processlist_status MTR test case

Because of the clang-formatting "};" is no longer located on a separate line
and therefore '/\};/' can no longer be an indicator of the end of the
'all_server_stages' array definition.

In addition, added support for "extern PSI_stage_info XXX;" declarations.

mysql-test/suite/rpl/t/rpl_perfschema_threads_processlist_status.test

@@ -103,19 +103,25 @@ perl;
       {
         $declared_stages{$1} = 1;
       }
+      # Read extern declaration.
+      elsif (/extern\s+PSI_stage_info\s+([A-Za-z_0-9]+)\s*;/)
+      {
+        $declared_stages{$1} = 1;
+      }
       # Figure out when we enter and leave the array initialization.
       elsif (/PSI_stage_info\s*\*\s*all_server_stages\s*\[/)
       {
         $in_server_stage_list= 1;
       }
-      elsif (/\};/) {
-        $in_server_stage_list= 0;
-      }
       # Read element from list.
       elsif ($in_server_stage_list &&
-             /\&\s*([A-Za-z_0-9]+)\s*,?/)
+             /\&\s*([A-Za-z_0-9]+)\s*(,|\};)/)
       {
         push(@listed_stages, $1);
+        if ($2 eq "};")
+        {
+          $in_server_stage_list= 0;
+        }
       }
     }
     close MYSQLD_CC or die "Error $? closing $mysqld: $!";