[clang] [llvm] [HIPSPV] Add in-tree SPIR-V backend support for chipStar (PR #206910)

[Prabhu Rajasekaran via cfe-commits]

Prabhuk wrote:

Given the fix forward https://github.com/llvm/llvm-project/pull/213052 was not reviewed and landed in a while. I am reverting  this PR to fix the buildbot failures. It is also impacting our toolchain builders at Google.

https://github.com/llvm/llvm-project/pull/206910