[Simh] even older PDP-10 macro

[Dave Dyer]

For my particular PDP-10 archeology, I need an even older version of
Macro-10 than I can find in the various archive tapes.  My recollection
is that I need version 47, which would have been current about 1975.

Either a binary or source would probably do.  I hope someone has an
image of a system tape from that era that was thought to be not important
because there were newer tapes available).

(back story;  Either macro 50+ had new bugs or Dec deliberately changed
the semantics of macros. In either case, a compile that had complicated
macros no longer worked on macro version 50+, and even in the day I had
to use "r old:macro" to compile.)