[llvm] [KnownBits] Remove `hasConflict()` assertions (PR #94568)

[via llvm-commits]

c8ef wrote:

> Though one testing-related change we should do is drop this check:
> 
> https://github.com/llvm/llvm-project/blob/574ab7e7b759a400ecf54c1141b1433bb2415e93/llvm/unittests/Support/KnownBitsTest.h#L29
> 
> This means the KnownBits implementation will actually get tested with conflict values, so we can be sure this doesn't produce unexpected crashes somewhere.

If we remove this check, it appears that *many* tests are failing. Currently, I am skipping values that have conflicts, but I am unsure if this is the correct approach. Please inform me if there are any issues.

https://github.com/llvm/llvm-project/pull/94568