Lazily allocate DexCache arrays.

We rarely need the DexCache for compiled code.
Delay the allocation in hope we never need it.

This reduces DexCache memory usage by ~25% at startup.

Test: m test-art-host-gtest
Test: test.py -r -b --host
Change-Id: I680a59c905c2b821ee954e4b32abd5d24876bd11
15 files changed