[llvm] [DebugInfo][NFC] Fix PDB/Native/LinePrinter.h build warning -Wmicrosoft-unqualified-friend (PR #209715)

[Carlos Alberto Enciso via llvm-commits]

CarlosAlbertoEnciso wrote:

Are you using MSVC or Clang and which options?
I used MSVC and no warning is generated.

https://github.com/llvm/llvm-project/pull/209715