[PATCH] D100151: Support: Use std::unique_ptr for SignpostEmitter::Impl, NFC

[Duncan P. N. Exon Smith via Phabricator via llvm-commits]

dexonsmith added a comment.

Apparently some hosts don't like using `std::unique_ptr` for types that only have forward declarations. Reverted in 078072285d3fbdaa94f9a91140eb5c1223b548af <https://reviews.llvm.org/rG078072285d3fbdaa94f9a91140eb5c1223b548af> and left a comment.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D100151/new/

https://reviews.llvm.org/D100151