* Provide some GNUisms as extensions.
* Provide dynamically growable string space.
* Make define(defn(foo)) work correctly for builtins.
(The current version is supposed to be capable of satisfying autoconf.)
All still relevant NetBSD changes have been preserved in this version, and
formatting and style fixes have been applied in various places.
Thanks to Masao Uebayashi <uebayasi@soum.co.jp> for pointing this out.
that typedef 'short'. 'char' (which was previously used) because char
may be unsigned and ((char)EOF) != EOF if that is the case. That was
causing the (char)EOF (0xff) pushed back in main to be interepreted as
a character, and, in some cases, to be written to the output. 'short'
was used rather than 'signed char' because if the latter is used,
0xff characters in the input would confuse m4. (No point in introducing
(more?) 8-bit lossage.)
