Ensure that all redefinition created dex file get on classpath

We were not adding some DexFiles to the ClassPath if there were
multiple classes from the same classloader being redefined at the same
time. We fixed this issue and made a test for it.

Test: mma -j40 test-art-host

Change-Id: I6e8961c8602367ebec5d5a948d71e58f3be2f6d7