Use of INCLUDE file (@) in a procedure causes segfaults on Apple arm64

[GillesDuvert]

on Apple arm64 (and only on arm64), having a command file included in a procedure (via the @ command) such as

 pro test
@include_commands.pro
 print,"test passed"
  end

will crash GDL. On other platforms, only a memory access problem is seen, and this by valgrind only.

Many, if not all, "serious" IDL packages use the @ liberally. These packages won't run on Apple M1 + GDL until this is fixed.
The bug exists since the beginnings of GDL and is linked to the persistence of data created by the Antlr Lexer.
Should be easy to fix.

This is why the mapping procedures (MAP_SET etc) currently crash on Apple arm64 arch.