[llvm] [Sparc] Remove bogus stack adjustment for LD/GD TLS (PR #149890)

[Rainer Orth via llvm-commits]

rorth wrote:

This would be very good to get into the `release/21.x` branch to make the Solaris/sparc9 `libomp` usable.

https://github.com/llvm/llvm-project/pull/149890