title: GCC compile fails with pthread and option std=c99
body: <p>I have an exemplar program that fails to compile with -std=c99</p>
  
  <p>any help appreciated</p>
  
  <pre><code>#include &lt;pthread.h&gt;
  int main(void) {
      pthread_rwlock_t    myLock;
      return 0;
  }
  
  output of the two compiles:
  gcc pthread_test.c
  [brad@fedora17onbradsmacpro src]$ gcc  pthread_test.c
  [brad@fedora17onbradsmacpro src]$
  
  gcc -std=c99 pthread_test.c[brad@fedora17onbradsmacpro src]$ gcc -std=c99 pthread_test.c
  pthread_test.c: In function ‘main’:
  pthread_test.c:5:2: error: unknown type name ‘pthread_rwlock_t’
  [brad@fedora17onbradsmacpro src]$
  </code></pre>