Add missing non-const value_ptr for quat

glm/gtc/type_ptr.inl

@@ -284,6 +284,17 @@ namespace glm
 		return &(mat[0].x);
 	}
 
+	//! Return the constant address to the data of the input parameter.
+	/// @see gtc_type_ptr
+	template<typename T, precision P>
+	GLM_FUNC_QUALIFIER T * value_ptr
+	(
+		detail::tquat<T, P> & q
+	)
+	{
+		return &(q[0]);
+	}
+
 	//! Return the constant address to the data of the input parameter.
 	/// @see gtc_type_ptr
 	template<typename T, precision P>