Update poly_atn

src/basic/math_trans/e33e.poly_atn.s

@@ -3,7 +3,12 @@
 ;; #LAYOUT# *  BASIC_0  #TAKE
 ;; #LAYOUT# *   *       #IGNORE
 
+; This file is under the MIT license, it contains code released by Microsoft Corporation.
+; See LICENSE for more information.
+
 ; Polynomial for the atn function
+;
+; This is verified to be identical to the original Microsoft implementation where it was named ATNCON
 
 
 !ifdef CONFIG_TRANSCENDENTAL_FUNCTIONS {