re: Fix non-termination for a certain regular expression

The following code never terminates:

fail() ->
     Str = "http:/www.flickr.com/slideShow/index.gne?group_id=&user_id=69845378@N0",
     EMail_regex = "[a-z0-9!#$%&'*+/=?^_`{|}~-]+"
       ++ "(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*"
       ++ "@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+"
       ++ "(?:[a-zA-Z]{2}|com|org|net|gov|mil"
       ++ "|biz|info|mobi|name|aero|jobs|museum)",
   io:format("about to run...~n"),
   Ret = re:run(Str, EMail_regex),
   io:format("Ret is ~p~n", [Ret]).

Fix it by having pcre_exec remember match_call_count between restarts.

Reported-by: Gordon Guthrie
Acked-by: Patrik Nyblom

erts/emulator/pcre/pcre_exec.c

@@ -5191,7 +5191,6 @@ for(;;)
       EDEBUGF(("Loop limit break detected"));
       return PCRE_ERROR_LOOP_LIMIT;
   RESTART_INTERRUPTED:
-      md->match_call_count = 0; 
       md->loop_limit = extra_data->loop_limit;
       rc = match(NULL,NULL,NULL,0,md,0,NULL,0,0);
       *extra_data->loop_counter_return =