[Debugify] Don't treat missing dbg.values as an error (PR37942)

When checking the debug info in a module, don't treat a missing
dbg.value as an error. The dbg.value may simply have been DCE'd, in
which case the debugger has enough information to display the variable
as <optimized out>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335647 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed