[ooc-compiler] Ported an application

[Alexander I. <aj...@ya...>]

Hello!

  I was able to port a console application ImportGraph (12 modules) based on Amadeus-3
  (XDS Oberon-2) to oo2c. I had to remove some of the functions from the ported modules
  and leave only the necessary parts in. That took one day and helped me discover quite
  a few differences between the two compilers.

  The resulting application is not portable, because it relies on non-portable modules from
  the Amadeus library, such as Files and Paths.

  The summary of how oo2c differs from the XDS discovered so far:
  - different pragmas and system flags;
  - no SYSTEM.GET and SYSTEM.PUT procedures;
  - no "--" wing comment;
  - ORD() can't be used on a BOOLEAN exression or variable, only on characters;
  - curly braces and some other characters in published comments ("(**...") must be escaped with "@";
  - no Out.Open procedure;
  - special string types: arrays, STRING type, CSTRING flag, NO_LENGTH_INFO and 
    NO_DESCRIPTOR flags. Also, the "STATIC_POINTER" flag, which is documented, but rejected
    by the compiler. Not sure yet how all these string (sub-)types get along with each other;
  - Win.SetFileTime accepts VAR [NIL_COMPAT] parameters of type Win.FILETIME, but it does not 
    accept variables of type POINTER TO Win.FILETIME as factual parameters;
  - can't use LONG() to promote an integer constant size;
  - SYSTEM.VAL can't be used in a constant declaration;
  - no typed SETs.

---=====---
 Alexander