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

[Paul Osmialowski via cfe-commits]

pawosm-arm wrote:

This is evident now. I've tried the commit just-before-the-one-introduced-by-this-PR and the commit-introduced-by-this-PR: the one before does not fail, the one introduced here does. @vrukesh should we revert this commit on the downstream release branch once it is being created later this week?

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