Support for large files > 2 GB by 64-bit functions

C/C++ programs are able to process large files (> 2 GB) if they have been compiled with a C/C++ compiler supporting the long long data type. The long long data type is part of any C/C++ compiler >= V3.1.

The maximal size of a BS2000 file is 4096 Gigabyte (= 4 Terabyte), a POSIX file may be maximal 1024 Gigabyte (= 1 Terabyte) in size.