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

[Alexis Engelke via llvm-commits]

https://github.com/aengelke commented:

Code LGTM with nit.

However, we should only do this once there is consensus on the options RFCs and in particular consensus on the question on whether we want add no- spellings and whether we want to keep =0/=1.

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