[llvm] [LLVM][DWARF] Make some effort to avoid duplicates in .debug_ranges. (PR #106614)

[Kyle Huey via llvm-commits]

khuey wrote:

This is IR from a pretty trivial Rust program that does some basic stuff with iterators.

[ir.txt](https://github.com/user-attachments/files/16808043/ir.txt)

If you run `llc -O2` on this without this patch you'll see a number of repeated debug ranges for successive inlines (e.g. .Ldebug_ranges3-9 are all the same).

https://github.com/llvm/llvm-project/pull/106614