Added support for std::ios::clear.

cfg/std.cfg

@@ -6031,6 +6031,14 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
       <not-uninit/>
     </arg>
   </function>
+  <!-- void std::ios::clear (std::ios::iostate state = std::ios::goodbit);-->
+  <function name="std::ios::clear,std::fstream::clear">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="1" default="std::ios::goodbit">
+      <not-uninit/>
+    </arg>
+  </function>
   <!-- istream& read (char* s, streamsize n); 
        ifstream& read (char* s, streamsize n); -->
   <function name="std::istream::read,std::ifstream::read">