Remove DexCache arrays from app oat .bss.

Their presence in the .bss was no longer necessary and
it doesn't really matter for memory usage whether they
are in the .bss or in the LinearAlloc. This removes
a lot of unnecessary code.

Test: m test-art-host
Test: testrunner.py --host
Change-Id: I63ccd4412fcb267341b8b012b7e3b09903f86625