[PATCH 0/4] More fixes to chew documentation

[Tom Tromey]

I re-read the chew-generated BFD info pages, and found a few more
issues.  This series fixes the simpler ones.

For patch #3, I looked at adding a GLOBAL directive to chew, to make
it possible to document bfd_use_reserved_id using @deftypevar.
However, because chew doesn't really implement conditionals, this
turns out to be surprisingly tricky.  It would be simpler to just turn
this global into a setter function instead -- there's just one spot in
ld that sets it.

Alternatively, maybe adding conditionals to chew is the way to go, as
that would also let us improve the documentation for macros.

Tom