Functions that take a boolean argument now properly type-check for it.

--HG--
branch : minor

src/common/runtime.h

@@ -125,6 +125,12 @@ bool luax_isarrayoftables(lua_State *L, int idx);
  **/
 bool luax_toboolean(lua_State *L, int idx);
 
+/**
+ * Returns the boolean value at idx. Causes a Lua error if the value is not
+ * a boolean.
+ **/
+bool luax_checkboolean(lua_State *L, int idx);
+
 /**
  * Pushes a bool onto the stack. It's the same as lua_pushboolean,
  * but with bool instead of int.