title: putchar_unlocked doesn't work in C++ 14 standard
body: <p>I am using g++ (GCC) 4.9.3 on Cygwin. I am not able to use <code>getchar_unlocked</code> or <code>putchar_unlocked</code> with C++ 14 standard.<br>
  Consider this sample code</p>
  
  <pre><code>#include &lt;cstdio&gt;
  
  int main() {
      putchar_unlocked('1');
      return 0;
  }
  </code></pre>
  
  <p>When I compile and run with</p>
  
  <pre><code>g++ foo.cpp &amp;&amp; a.exe &amp;&amp; rm ./a.exe
  </code></pre>
  
  <p>I am getting expected output 1.<br>
  But when I do</p>
  
  <pre><code>g++ -std=c++14 foo.cpp &amp;&amp; a.exe &amp;&amp; rm ./a.exe
  </code></pre>
  
  <p>I am getting error saying putchar_unlocked was not declared.</p>
  
  <pre><code>foo.cpp: In function 'int main()':
  foo.cpp:4:22: error: 'putchar_unlocked' was not declared in this scope
    putchar_unlocked('1');
                        ^
  </code></pre>