Tucker responds that one possibility for solving the non-portability
of the pragma stdcall under some operating systems is

   > a general capability to define a renaming for pragma arguments

Such a pragma would also solve the problem of making portable software
that can switch package bodies for different operating systems or
hardwares. A pragma USE_PACKAGE BODY ("APPLE.ADB") could be
ARGUMENT_DEFINEd to later be "NT.ADB" or "MIPS.ADB" or "SILICON_GRAPHICS.ADB".