I tested the proposed patch with a simple .exe containing TLS variables the attached patch is needed on top of yours to make it work[missing](/uploads/42cc9b24aa94243c17ef04dceb509163/missing) (and it could be better written <g>)
I still think we do too many things just to get the address of the tls. This calls for shadowing in winedbg some module information (here this could be the address of AddressOfIndex).