compiling 1.5 with -current toolchain

["Darrin B. Jewell" <dbj%netbsd.org@localhost>]

I recently attempted to build a 1.5 macppc kernel from a -current
system.  Although the kernel compiled and linked without error or
warning, it would not boot.  I debugged this enough to determine that
it was dying in or around OF_call_method, the first varargs function
that it encountered.  After looking at the CVS revision history for
sys/arch/powerpc/include/stdarg.h, I realized that the 1.5 branch does
not have varargs updates required to work with the new compiler.

It it appropriate to pull up changes to stdarg.h to the 1.5 branch
so that the -current compiler can compile the 1.5 branch?  Are there
other changes that would need to be pulled up as well?

I'm currently thinking that we should not pull up these changes, but
should add a compile time error to stdarg.h that will warn at compile
time that it will not work.

Which is appropriate?

Darrin