std.cfg: Added support for swprintf().

cfg/std.cfg

@@ -5238,6 +5238,17 @@
       <formatstr/>
     </arg>
   </function>
+  <!-- int swprintf(wchar_t *s, size_t n, const wchar_t *format, ...); -->
+  <function name="swprintf">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <arg nr="2">
+      <not-uninit/>
+    </arg>
+    <arg nr="3">
+      <not-null/>
+    </arg>
+  </function>
   <!-- int vsprintf(char *s, const char *format, va_list arg); -->
   <function name="vsprintf">
     <noreturn>false</noreturn>