[llvm] [WebAssembly] Use DebugValueManager only when subprogram exists (PR #77978)

[Derek Schuff via llvm-commits]

dschuff wrote:

Thanks, this change LGTM and yeah I concur with all of your analysis about DebugValueManager's behavior. I think it does make sense for now to just limit the "lookahead" range for `DBG_VALUE`s. I would imagine that practically speaking we could get nearly all of the benefits of the lookahead even with a limit in the hundreds of instructions or something. Maybe we could just pick the value based on how much faster it makes the example in the bug? 

https://github.com/llvm/llvm-project/pull/77978