[llvm] [llvm-gsymutil] Print one-time DWO file missing warning under --quiet flag (PR #79882)

[David Blaikie via llvm-commits]

dwblaikie wrote:

FWIW, these days we tend to avoid checking in binaries for testing these tools - instead checking in assembly and generating dwarf objects from that in the test with llvm-mc, or similar pipelines, where possible.

https://github.com/llvm/llvm-project/pull/79882