[llvm] [ADT] Add `from_range` constructor for (Small)DenseMap (PR #153515)

[Jakub Kuderski via llvm-commits]

kuhar wrote:

The test failure is unrelated to the PR: https://github.com/llvm/llvm-project/actions/runs/16952985682/job/48049492813?pr=153515#step:3:12501

https://github.com/llvm/llvm-project/pull/153515