Update const_PI

Allow a patched best rounded value or the original value from the MS BASIC

src/basic/math_consts/aea8.const_PI.s

@@ -3,12 +3,23 @@
 ;; #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.
+
+; Math package - The floating point constant PI
+;
+; This is verified to be identical to the original Microsoft implementation where it was named PIVAL.
 ;
-; Math package - a constant, for documentation see:
 ; - https://www.c64-wiki.com/wiki/BASIC-ROM
 ; - Computes Mapping the Commodore 64, page 103
 ;
 
 const_PI:
 
+; The original BASIC didn't have the most accurate PI.
+
+!ifdef CONFIG_ORIGINAL_UNPATCHED_BASIC {
+    +PUT_CONST_PI_MS
+} else {
 	+PUT_CONST_PI
+}