The documentation system these were from was removed from SWIG 23 years
ago - the %subsection directive now only emits a warning, and the %text
directive is a functional no-op.
The text in these directives seems useful to keep so just convert them
to comments.
Presumably nobody noticed because these remaining uses were all
protected by `#ifdef AUTODOC` which nothing now defines.
This was renamed to %extend 21 years ago!
The remaining uses are either in docs for the reference example or in
xml examples (which can't actually be run because they the SWIG command
line syntax they try to use is wrong).
The XML target language support is not in good shape and is likely to be
removed unless somebody steps up to bring it up to the expected standard
(it fails to even meet the criteria for "Experimental" currently).
Closes#2213
Remove redundant NULL checks before free()/delete
The ISO C and C++ standards guarantee that it's safe to call these
on a NULL pointer, so it's not necessary for the calling code to
also check.
Fixes https://sourceforge.net/p/swig/feature-requests/70/
Olly Betts