Most warnings are for functions implicitly returning int. Change most
of these functions to return void. (Traditional K&R C had no void
type, but C89 has it.)
Add prototypes to most function declarations in headers. This is
easy, because ego declares most of its extern functions, and the
comments listed most parameters. There were a few outdated or missing
declarations, and a few .c files that failed to include an .h with the
declarations.
Add prototypes to a few function definitions in .c files. Most
functions still have traditional K&R definitions. Most STATIC
functions still don't have prototypes, because they have no earlier
declaration where I would have added the prototype.
Change some prototypes in util/ego/share/alloc.h. Functions newmap()
and oldmap() handle an array of pointers to something; change the
array's type from `short **` to `void **`. Callers use casts to go
between `void **` and the correct type, like `line_p *`. Function
oldtable() takes a `short *`, not a `short **`; I added the wrong type
in 5bbbaf4.
Make a few other changes to silence warnings. There are a few places
where clang wants extra parentheses in the code.
Edit util/ego/ra/build.lua to add the missing dependency on ra*.h; I
needed this to prevent crashes from ra.
