Notable side effects:
* Use the standard-conformant MSVC preproc
* Add test for linker script INCLUDE
* Improve wording of placement conflict errors
* Fix errors from not newline-terminated files
* Teach checkdiff about the linker script doc
* Call linker script "commands" "directives" instead
---------
Co-authored-by: Rangi42 <remy.oukaour+rangi42@gmail.com>
As reported by the following command:
mandoc -T lint man/* | grep -v "input text line longer than 80 bytes"
(One of them also showed up as a warning while setting up Debian packaging.)
