Change class set search order in `ClassTable`.

Insert image class tables before the last, unfrozen, table
and search the tables from the back. Image tables are still
searched in the same order as before (namely in reverse
insertion order) but the unfrozen table is searched first
(instead of last) and the frozen zygote table is searched
between app image tables and boot image tables (instead of
second last).

This implements the same search order for `ClassTable` as
was implemented for `InternTable` by two changes:
    https://android-review.googlesource.com/2054005 ,
    https://android-review.googlesource.com/2059788 .

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 181943478
Change-Id: I8af3860fc5d6d19e85eb5d8df845ca5b9ddf11b6
1 file changed