Improve regex performance on msvc by removing statically allocated recursion stack, and using a std::vector instead.

[SVN r59414]

performance/command_line.cpp

@@ -100,6 +100,9 @@ int handle_argument(const std::string& what)
 #endif
 #ifdef BOOST_HAS_PCRE
       time_pcre = true;
+#endif
+#ifdef BOOST_HAS_XPRESSIVE
+      time_xpressive = true;
 #endif
    }
    else if(what == "-test-matches")