Add option to not look %include in current work directory

[xclaesse]

As per https://www.nasm.us/doc/nasm02.html#section-2.1.18, NASM looks for includes in CWD as well as in -i paths.

Build systems like Ninja invokes all commands from the top build directory. That means that if a config.asm is placed there, it will be used by NASM even if we want to include another config.asm in some other path defined by -i subdir/.

Would it be possible to add a command line option to disable looking in current directory, e.g. --no-include-cwd? It would still be possibly to look in current directory with -i . which is AFAIK how other compilers such as GCC works.

[xclaesse]

Note that it could be enough to simply make -i paths take precedence over current directory.

[hpax]

It should be reasonable to do, but it isn't quite as simple as it might sound, because of the way NASM caches directory lookups.