[clang] [CIR] Implement the 'rest' of the TLS Model types (PR #215380)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

Thanks for the comments @bcardosolopes , I think you found a decent hole in my understanding of all of these.

I DID add all the tests and do most of the changes you suggested, so if you could review it again I'd be very appreciative.  

I also changed the name to tls_refs because of your other comments :)  

The one thing I skipped was the Darwin Thread Wrapper linkage determination.  I couldn't get a test to work with a darwin triple because I don't think we have enough of the target info implemented, so I left an NYI there instead. 

https://github.com/llvm/llvm-project/pull/215380