PR4186: cross-compilation, $ARCH

[Frank Ch. Eigler]

Hi -

> [...]
> - Are we planning on extending '%arch' (or perhaps adding '%user_arch')
> to tell the difference between 32-bit and 64-bit user exes?

This would makes sense only as a per-probe-point construct, since the
same stap script on a 64-bit host can instrument 32- and 64-bit
userspace programs just fine.


> - I'd probably go with solution #2 [switching to kernel "arch"], but
> also provide "aliases" for the old names (assuming that's possible).

I don't know.  We'd have to handle things like
  %( arch == "i686" %? /*A*/ %: /*B*/ %) 
and also
  %( arch == "i686" %? /*A*/ %: %( arch == "i386" %? /*B*/ %: /*C*/ %) %)

- FChE