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

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

I see...

But then if we already need to set `llvm::TimePassesIsEnabled` to get backend timers, this PR makes the middle end and backend diverge and now there are two things you need to do to enable timers (set `llvm::TimePassesIsEnabled` and set the `StandardInstrumentations` constructor) instead of one. Ideally we'd get both the middle end and backend in a similar state to enable timers?

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