IIUC functions syms_of_XXX, keys_of_YYY and init_ZZZ_once are never
called in a normal (dumped) executable; so what's about putting them
into a special section and strip the latter at all?  This patch
illustrates an idea, with yet another make-docfile trick.  (Also we
can offload lisp.h and other headers from declarations which are easy
to generate and put into globals.h instead).

Dmitry