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

[Nikita Popov via llvm-commits]

nikic wrote:

These assertions are not just in KnownBits.h, but also spread across many other places. Basically do a `git grep "hasConflict()"` (There are currently 88 occurrences, though not all of them are in assertions.)

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