ART: Skip duplicate classes during compilation

If a class doesn't resolve to the current dex file, processing can be
skipped. It must have been handled before.

For a large test app, compiling with -j1, compile phase only:

          Before    After
Quicken   14.270   13.541
Speed    156.621  153.591

Bug: 78201536
Test: m test-art-host
Change-Id: Ia5df3f7f6da2be114a5e9051c18d5716a5f48515