[clang-tidy] New check: Remove redundant comparison operators

[SunBlack]

Since C++20 rewriting rules exists, so that it is e.g. not anymore necessary to define operator!= when operator== already exists.

I hope that the compilers will optimize accordingly, so that the rewrite rule is always as fast as the manual rule (as an example: If there used to be a!=b and a==b and you remove the former rule, that the compiler does not make !(a==b) out of it, i.e. 2 assembler instructions instead of one).

SonarLint already have a check for this, so that you could spot what could also be adjusted.

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: SunBlack (SunBlack)

Since C++20 rewriting rules exists, so that it is e.g. not anymore necessary to define `operator!=` when `operator==` already exists.

I hope that the compilers will optimize accordingly, so that the rewrite rule is always as fast as the manual rule (as an example: If there used to be a!=b and a==b and you remove the former rule, that the compiler does not make !(a==b) out of it, i.e. 2 assemler instructions instead of one).

SonarLint already have a check for this, so that you could spot what could also be adjusted.

[vbvictor]

Do you suggest implementing a new check?