[llvm] [DebugInfo] Keep validating after register and entry-value ops (PR #214057)

[Matt Davis via llvm-commits]

https://github.com/enferex approved this pull request.

+1 from me, please wait for @ayermolo approval prior to landing.  In general it seems reasonable to continue the expression validity testing, especially with the upcoming change in semantics from DWARFv6 (e.g., no more "A register location description must stand alone as the entire description of an object or a piece of an object.")

https://github.com/llvm/llvm-project/pull/214057