Fix oatwriter code deduping

Now that the GC maps are part of the oat method header they need
to be checked in CodeOffsetsKeyComparator.

Bug: 18523556

Change-Id: I539a6e7216166342b22515c1e2cf831dad32e41e

(cherry picked from commit 4cdf4508903d13fd0f9fba5690aeac1b368db81b)
2 files changed