[llvm] [ADT] Update hash function of uint64_t for DenseMap (PR #95734)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@ChuanqiXu9 I'm seeing warnings on MSVC builds:
```
E:\llvm\llvm-project\llvm\include\llvm/ADT/DenseMapInfo.h(145): error C2220: the following warning is treated as an error
E:\llvm\llvm-project\llvm\include\llvm/ADT/DenseMapInfo.h(145): warning C4293: '>>': shift count negative or too big, undefined behavior
```

https://github.com/llvm/llvm-project/pull/95734