[clang] [Clang][HIP] Remove 'clangPostLink' from SDL handling (PR #67366)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

Long term I'd like to move HIP to the new driver so we can delete all of this SDL handling code. That would require someone guiding me through how to test the toolchain on Windows so I can make the linker wrapper work with the Windows linker.

https://github.com/llvm/llvm-project/pull/67366