[clang] [PS5] Enable support for DTLTO in the PS5 Clang driver (PR #158041)

[Jeremy Morse via cfe-commits]

https://github.com/jmorse approved this pull request.

LGTM with some nits inline; I'd leave the final nod to @playstation-edd as he's done more driver work lately.

https://github.com/llvm/llvm-project/pull/158041