Apply `CompilerDriver::LoadImageClasses()` to app images.

Resolving and pruning image classes is necessary to make the
`CompilerOptions::IsImageClass()` correct for app images.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing --speed-profile
Bug: 38313278
Change-Id: Iac8eb867101433ced6d9dba82ec8968fc0e58946
7 files changed