[Patch, libstdc++/64441] Fix sub_match::first and second

[Tim Shen]

A dumb mistake :)

Bootstrapped and tested.

Thanks!

-- 
Regards,
Tim Shen

commit 7fc4b45bb9cf6b1c6ec6620092ae18fe41cb57af
Author: timshen <tims...@google.com>
Date:   Tue Dec 30 21:14:48 2014 -0800

    2014-12-30  Tim Shen  <tims...@google.com>

      PR libstdc++/64441
      * include/bits/regex.tcc (__regex_algo_impl): s/auto/auto&/.
      * include/bits/regex_executor.tcc (_Executor<>::_M_dfs): Likewise.

diff --git a/libstdc++-v3/include/bits/regex.tcc 
b/libstdc++-v3/include/bits/regex.tcc
index 0206a6c..b541446 100644
--- a/libstdc++-v3/include/bits/regex.tcc
+++ b/libstdc++-v3/include/bits/regex.tcc
@@ -96,7 +96,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  }
       if (__ret)
  {
-   for (auto __it : __res)
+   for (auto& __it : __res)
      if (!__it.matched)
        __it.first = __it.second = __e;
    auto& __pre = __res[__res.size()-2];
diff --git a/libstdc++-v3/include/bits/regex_executor.tcc 
b/libstdc++-v3/include/bits/regex_executor.tcc
index a973667..7954d06 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -310,7 +310,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
      if (!__submatch.matched)
        break;
      auto __last = _M_current;
-     for (auto __tmp = __submatch.first;
+     for (auto& __tmp = __submatch.first;
     __last != _M_end && __tmp != __submatch.second;
     ++__tmp)
        ++__last;