Revert "follow-up 3"

This reverts commit cd57dfa5ff.

sys/share/cppregex.cpp

@@ -63,13 +63,3 @@ extern "C" {
     delete re;
   }
 }
-
-void
-regex_at_exit(void)
-{
-    if (cppregex_static_buffer != 0) {
-        free((genericptr_t) cppregex_static_buffer);
-        cppregex_static_buffer = (char *) 0;
-    }
-}
-