Update const_PI

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

tools/similarity.c

@@ -20,9 +20,10 @@ int matches[MAX_SIZE];
 
 int phase_mask[MAX_SIZE+MAX_SIZE];
 
-#define NUM_CHUNKS 13
+#define NUM_CHUNKS 14
 // Pairs of start, end memory addresses of known exact similarity with the open source Microsoft BASIC
 unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {
+    0xAEA8, 0xAEAC,
     0xB248, 0xB24C,
     0xB391, 0xB39D,
     0xB3A2, 0xB3A5,