[llvm] [dsymutil] Fix parallel linker's self-recursive typedef DIE (PR #166675)

[Michael Buch via llvm-commits]

https://github.com/Michael137 commented:

Conceptually it makes sense to not merge the DIEs since they aren't the same. Also typedefs are the only construct that i can think of atm that would allow two distinct entities with the same name. I guess technically it's a redeclaration?

I dont think we should look at line numbers though. For one, a dwarf producer may omit them. And as you say, two typedefs may be declared on the same line

Could we include the canonical referred-to type in the synthetic name? I.e unwrap the typefed type?

https://github.com/llvm/llvm-project/pull/166675