More specifically:
1) Use variable after move.
2) steady_clock needs to be used for measuring time intervals, but not the system_clock.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D106513
This factors out the pass timing code into a separate `TimingManager`
that can be plugged into the `PassManager` from the outside. Users are
able to provide their own implementation of this manager, and use it to
time additional code paths outside of the pass manager. Also allows for
multiple `PassManager`s to run and contribute to a single timing report.
More specifically, moves most of the existing infrastructure in
`Pass/PassTiming.cpp` into a new `Support/Timing.cpp` file and adds a
public interface in `Support/Timing.h`. The `PassTiming` instrumentation
becomes a wrapper around the new timing infrastructure which adapts the
instrumentation callbacks to the new timers.
Reviewed By: rriddle, lattner
Differential Revision: https://reviews.llvm.org/D100647
rdzhabarov