[llvm] [LLVM][ADT] Convert llvm::hash_code to unsigned explicitly in DenseMapInfo (PR #77743)

[Andrei Golubev via llvm-commits]

andrey-golubev wrote:

@lattner @dwblaikie @joker-eph @River707 @silvasean judging from your "recent" activity in the area, you might be good reviewers here. Please feel free to add any other person who might be more suitable.

https://github.com/llvm/llvm-project/pull/77743