Mass rename C1x references to C11. The name hasn't proliferated like "C++0x" so this patch is surprisingly small.

Also drop -Wc1x-extensions in favor of -Wc11-extensions. I don't think we need to keep this around for compatibility.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147221 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LanguageExtensions.html b/docs/LanguageExtensions.html
index f8c0d4f..1218d46 100644
--- a/docs/LanguageExtensions.html
+++ b/docs/LanguageExtensions.html
@@ -72,11 +72,11 @@
     <li><a href="#cxx_user_literals">C++11 user-defined literals</a></li>
     <li><a href="#cxx_variadic_templates">C++11 variadic templates</a></li>
    </ul></li>
-  <li><a href="#c1x">C1X</a>
+  <li><a href="#c11">C11</a>
     <ul>
-    <li><a href="#c_alignas">C1X alignment specifiers</a></li>
-    <li><a href="#c_generic_selections">C1X generic selections</a></li>
-    <li><a href="#c_static_assert">C1X <tt>_Static_assert()</tt></a></li>
+    <li><a href="#c_alignas">C11 alignment specifiers</a></li>
+    <li><a href="#c_generic_selections">C11 generic selections</a></li>
+    <li><a href="#c_static_assert">C11 <tt>_Static_assert()</tt></a></li>
     </ul></li>
   </ul> </li>
 <li><a href="#checking_type_traits">Checks for Type Traits</a></li>
@@ -659,33 +659,33 @@
 <tt>__has_extension(cxx_variadic_templates)</tt> to determine if support
 for variadic templates is enabled.</p>
 
-<h3 id="c1x">C1X</h3>
+<h3 id="c11">C11</h3>
 
 <p>The features listed below are slated for inclusion in the upcoming
-C1X standard. As a result, all these features are enabled
-with the <tt>-std=c1x</tt> option when compiling C code.</p>
+C11 standard. As a result, all these features are enabled
+with the <tt>-std=c11</tt> option when compiling C code.</p>
 
-<h4 id="c_alignas">C1X alignment specifiers</h4>
+<h4 id="c_alignas">C11 alignment specifiers</h4>
 
 <p>Use <tt>__has_feature(c_alignas)</tt> or <tt>__has_extension(c_alignas)</tt>
 to determine if support for alignment specifiers using <tt>_Alignas</tt>
 is enabled.</p>
 
-<h4 id="c_generic_selections">C1X generic selections</h4>
+<h4 id="c_generic_selections">C11 generic selections</h4>
 
 <p>Use <tt>__has_feature(c_generic_selections)</tt> or
 <tt>__has_extension(c_generic_selections)</tt> to determine if support for
 generic selections is enabled.</p>
 
-<p>As an extension, the C1X generic selection expression is available in all
+<p>As an extension, the C11 generic selection expression is available in all
 languages supported by Clang.  The syntax is the same as that given in the
-C1X draft standard.</p>
+C11 standard.</p>
 
 <p>In C, type compatibility is decided according to the rules given in the
 appropriate standard, but in C++, which lacks the type compatibility rules
 used in C, types are considered compatible only if they are equivalent.</p>
 
-<h4 id="c_static_assert">C1X <tt>_Static_assert()</tt></h4>
+<h4 id="c_static_assert">C11 <tt>_Static_assert()</tt></h4>
 
 <p>Use <tt>__has_feature(c_static_assert)</tt> or
 <tt>__has_extension(c_static_assert)</tt> to determine if support for