[llvm] [OpenMP][Offload] Add a buffer layer to debug messaging (PR #172446)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

What's the issue exactly? the old printf interface didn't have gaps in it because `printf` formats one big string and does it at once. Any way we can get the same thing by outputting to a temporary string buffer and dumping it at once?

https://github.com/llvm/llvm-project/pull/172446