[llvm] [RemoveDIs][DebugInfo] Add DPValue checks to the verifier, prepare DPValue for parsing support (PR #79810)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

> Is it worth shuffling in the code in BasicBlock::validateDbgValues into the main Verifier now too?

I've got this done now, but just a question for you since you added it - currently this check is a hard error in the verifier, should we change it now to a debug info error instead?

https://github.com/llvm/llvm-project/pull/79810