Fix for failure of ma_test_loghandler_long-t on Windows

dbug/dbug.c:
  importing change from 6.0, which speeds up --debug on Windows (no sync)
storage/maria/unittest/ma_test_loghandler-t.c:
  this test needs ~80 open files (logs)

dbug/dbug.c

@@ -1979,12 +1979,7 @@ static void DBUGOpenFile(CODE_STATE *cs,
       else
       {
         newfile= !EXISTS(name);
-        if (!(fp= fopen(name,
-#if defined(MSDOS) || defined(__WIN__)
-		append ? "a+c" : "wc"
-#else
-                append ? "a+" : "w"
-#endif
+        if (!(fp= fopen(name, append ? "a+" : "w")))
 		)))
         {
           (void) fprintf(stderr, ERR_OPEN, cs->process, name);

storage/maria/unittest/ma_test_loghandler-t.c

@@ -151,6 +151,11 @@ int main(int argc __attribute__((unused)), char *argv[])
 
   MY_INIT(argv[0]);
 
+  if (my_set_max_open_files(100) < 100)
+  {
+    fprintf(stderr, "can't allocate 100 file descriptors\n");
+    exit(1);
+  }
   bzero(&pagecache, sizeof(pagecache));
   maria_data_root= (char *)".";
   if (maria_log_remove())