[clang] [DTLTO][TEST] Get the DTLTO Clang driver tests failing on some buildbots to pass (PR #159158)

[Jan Patrick Lehr via cfe-commits]

jplehr wrote:

On our bot, I cleaned both source and build tree and gave that a go.
It seems that this helped in our case. Maybe something simply left some stale data around?

https://github.com/llvm/llvm-project/pull/159158