- use `UNITTEST_BEGIN_SIMPLE`/`UNITTEST_END_SIMPLE` where missing.
- drop redundant `(void)arg;` where using `UNITTEST_BEGIN*`.
- unit1636: drop redundant block after `UNITTEST_BEGIN*`.
- unit1609: fix typo in comment.
- unit1627: merge to `if`s.
Closes#21715
- examples: sync debug output printf masks.
- INSTALL-CMAKE.md: tidy up section for some options.
- curl_sha512_256: delete comment suggesting an optimization.
- vtls/keylog: scope a variable.
- vtls/openssl: make a source code URL a permalink.
- vtls/schannel: drop redundant parentheses.
- test1119.pl: robustify `$1` -> `$s`.
- sync arg names in comments to match the code.
- tidy up and minor fixes to comments.
- fix formatting/indenting/comment/newline/include nits.
- move `UNITTEST` protos next to definitions, sync their argument names.
- make variables static.
- add parentheses to Perl `open()` calls.
- drop unnecessary double quotes in Perl.
- clang-format.
Closes#21000
