Added small subset of MISRA C++:2008 rules that can be checked using clang-tidy

[PetervdPerk-NXP]

This is to keep the discussion going that @Igor-Misic started this week, I was thinking we should first try to utilize free OSS to implement some basic MISRA rules checking, before considering commercial tooling.

This patch adds the make misra-basic target, that tests some Misra rules using clang-tidy.

This can be extended by CppCheck as well, however CppCheck can't check on rule basis but generates an complete overview. But it's addons module does implement a nice set of Misra C rules see https://github.com/danmar/cppcheck/blob/main/addons/misra.py

[mrpollo]

Thanks for the push on this end @PetervdPerk-NXP great work!

Should we add a check on CI?

[PetervdPerk-NXP]

Hm I think if we add this to the CI it will trigger a lot of errors.

I would rather use this target as a staging area of rules that can be reviewed and later a review should take place to decide which rules should be integrated into the .clang-tidy file which are used in the CI already.

Like @dagar showcased here https://github.com/PX4/PX4-Autopilot/runs/2029824398 the CI already runs make clang-tidy-quiet

[mrpollo]

@PetervdPerk-NXP hey I think it's best if you integrate this into the current clang-tidy CI build, and close this PR, what do you think?

[PetervdPerk-NXP]

This will trigger a lot of errors though, would that be a problem for the clang-tidy CI?
Furthermore should this be enforce on code styling/formatting already? @Igor-Misic is it already decided PX4 is going to follow the MISRA coding standard and which version then?

[Igor-Misic]

@Igor-Misic is it already decided PX4 is going to follow the MISRA coding standard and which version then?

Nothing decided yet. At the dev call where this was topic was discussed it will probably never be fully adopted, but maybe just subsets. I am happy if people just keep this topic in mind.

I've seen many different coding styles here so far so not sure what would be next to god step. Maybe to do fork and rewrite everything xD