[llvm] [SPIRV] convergence anchor intrinsic does not have a parent token (PR #122230)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

As a concession to existing SPIRV implementation, added an assert that catches any incorrectly placed tokens on the anchor and entry intrinsics at this point. Anything that trips this assert is a bug in the use of these intrinsics and needs to be fixed separately. I don't think anything more is possible in this patch.

https://github.com/llvm/llvm-project/pull/122230