[clang] [llvm] Reland "[ORC] Track __emutls_t definitions in IRMaterializationUnit" (#207161) (PR #208413)

[Emery Conrad via cfe-commits]

conrade-ctc wrote:

> > @vgvassilev @lhames — could you take a look?
> 
> 
> 
> Can you not put github handles in the pr description because they become part of the commit log and then we get pinged on fork pulls..

Ah, I was unaware of that! I just removed from the PR description after you merge, hope it's JIT ;)

https://github.com/llvm/llvm-project/pull/208413