[llvm] [InstrRef] Skip clobbered EntryValue register recovery (PR #142478)

[Shubham Sandeep Rastogi via llvm-commits]

rastogishubham wrote:

@jmorse @adrian-prantl 

I got the patch working how Jeremy wanted. We now use the `recoverAsEntryValue` path if the location is not available at the start of the block, however, we also filter the `ActiveVLocs` and the `ActiveMLocs` if the location is available at the start of the block

https://github.com/llvm/llvm-project/pull/142478