FFI 64 bit updates - win32 and unix both work now

 
--- Status of updates for 32/64 bit clean FFI ---

I updated the Windows platform sources and verified that the Windows examples
run and all unit tests are green.  I also updated the unix platform sources for
Mac and verified clean compiles, although I do not have have a machine on which
to test these changes.  I have not done anything for Mac OS platform sources, but
I expect the changes to be straightforward (John, are you interested in looking
at this?).

Overall changes involve:
 - Add FFIPlugin>>primitiveSizeOfPointer for runtime address size check
 - ExternalAddress is either 4 or 8 bytes wide, initialized at image startup
 - Remove all casts from pointer to int for FFI plugin and interpreter
   (VM minor version bump)
 - Recompile all methods with cdecl or apicall pragmas (must to done for any
   image to run properly on 64 bit host)

Platform FFI testing as of
Mon May 26 14:26:22 EDT 2008
"GREEN" means no compiler warnings, all SUnits pass, and the X11/Win32 examples work.

======================================================================================================
VM     config.guess             FFI implementiation             host     image      status
--     ------------             -------------------             ----     -----      ------
win32  32 bit Windows on AMD64  sqWin32FFI.c                    32 bit   32 bit     GREEN
win32  32 bit Windows on AMD64  sqWin32FFI.c                    32 bit   64 bit     tbd
unix   i686-pc-linux-gnu        x86-sysv.c+x86-sysv-asm.S       32 bit   32 bit     GREEN
unix   i686-pc-linux-gnu        x86-sysv.c+x86-sysv-asm.S       32 bit   64 bit     GREEN
unix   i686-pc-linux-gnu        any-libffi.c                    32 bit   32 bit     GREEN
unix   i686-pc-linux-gnu        any-libffi.c                    32 bit   64 bit     GREEN
unix   x86_64-unknown-linux-gnu any-libffi.c                    64 bit   32 bit     GREEN
unix   x86_64-unknown-linux-gnu any-libffi.c                    64 bit   64 bit     GREEN
unix   x86_64-unknown-linux-gnu x86_64-sysv.c+x86_64_sysv-asm.S 64 bit   32 bit     Not implemented(*)
unix   x86_64-unknown-linux-gnu x86_64-sysv.c+x86_64_sysv-asm.S 64 bit   64 bit     Not implemented(*)
unix                            ppc-darwin.c+ppc-darwin-asm.S   ?        32 bit     Needs testing(**)
unix                            ppc-darwin.c+ppc-darwin-asm.S   ?        64 bit     Needs testing(**)
unix                            ppc-sysv.c+ppc-sysv-asm.S       ?        32 bit     Needs testing(**)
unix                            ppc-darwin.c+ppc-darwin-asm.S   ?        64 bit     Needs testing(**)
Mac OS ... (should be easy update)
RiscOS ... (no FFI implementation?)

(*) Is anyone willing and/or able to write a x86_64_sysv-asm.S? I could do the
corresponding x86_64-sysv.c, but could use some help on how to set up a 64 bit
call stack in assembler, never did that before.

(**) C code changes implemented. Compiles on Linux, but not tested on target
platform. Need somebody with a PPC Mac to try this.