[llvm] [ADT] Add DenseSet(llvm::from_t, Range) (PR #131832)

[Kazu Hirata via llvm-commits]

kazutakahirata wrote:

> > while forward-porting std::from_range from c++23.
> 
> Could you describe (or link to) what `std::from_range` is and explain why we'd want to use it in llvm?

Sure:

https://en.cppreference.com/w/cpp/ranges/from_range

`std::from_range` clearly indicates that the immediately following argument is a range and makes sure that the correct constructor is picked.


https://github.com/llvm/llvm-project/pull/131832