Refactored optimization passes setup.

Rationale:
Refactors the way we set up optimization passes
in the compiler into a more centralized approach.
The refactoring also found some "holes" in the
existing mechanism (missing string lookup in
the debugging mechanism, or inablity to set
alternative name for optimizations that may repeat).

Bug: 64538565

Test: test-art-host test-art-target
Change-Id: Ie5e0b70f67ac5acc706db91f64612dff0e561f83