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

[Jeremy Morse via llvm-commits]

jmorse wrote:

I suppose one of the awkward things about this area is how the entry-value flag affects different pieces of code -- in an ideal world we would represent entry-value locations in some /other/ way than "a reference to a register that isn't really a reference". But this is how it works today!

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