bpo-42739: Don't use sentinels to mark end of line table. (GH-25657)

* Add length parameter to PyLineTable_InitAddressRange and doen't use sentinel values at end of table. Makes the line number table more robust.

* Update PyCodeAddressRange to match PEP 626.

Python/compile.c

@@ -6959,10 +6959,6 @@ assemble(struct compiler *c, int addNone)
     if (!assemble_line_range(&a)) {
         return 0;
     }
-    /* Emit sentinel at end of line number table */
-    if (!assemble_emit_linetable_pair(&a, 255, -128)) {
-        goto error;
-    }
 
     if (_PyBytes_Resize(&a.a_lnotab, a.a_lnotab_off) < 0) {
         goto error;

Python/frozen_hello.h

@@ -8,5 +8,5 @@ const unsigned char _Py_M__hello[] = {
     5,112,114,105,110,116,169,0,114,1,0,0,0,114,1,0,
     0,0,122,14,60,102,114,111,122,101,110,32,104,101,108,108,
     111,62,218,8,60,109,111,100,117,108,101,62,1,0,0,0,
-    115,6,0,0,0,4,0,12,1,255,128,
+    115,4,0,0,0,4,0,12,1,
 };