[llvm] [Support] Accept -no-<name> to negate cl::opt<bool> (PR #224978)

[Nikita Popov via llvm-commits]

nikic wrote:

> This PR is addition, -x=false|0 is not taking away.

The PR description still claims:

> In the future, we shall ban -<name>=false and -<name>=0 for boolean options. See https://discourse.llvm.org/t/91877

I also don't think this should be conflated with the options RFC. I don't believe that changing the style of boolean options is at all necessary to realize that RFC, beyond some tiny implementation convenience.

https://github.com/llvm/llvm-project/pull/224978