[llvm] [llvm][Support] Enable pass timing in StandardInstrumentations constr… (PR #108983)

[Tarun Prabhu via llvm-commits]

tarunprabhu wrote:

Closing this since @aeubanks concerns are valid. One ends up having to do two different things since the legacy pass manager used by the backend still requires global variables to be set in order to enable timings. A different approach may be warranted.

https://github.com/llvm/llvm-project/pull/108983