Reduce memory allocations in dexlayout's CodeFixups.

Using heaptrack for the services.odex compilation of
aosp_taimen-userdebug:
  - before: calls to allocation functions: 5032880
  - after: calls to allocation functions: 4645378

Test: Rely on TreeHugger
Bug: 70331349
Change-Id: I477d5a84e0bf22994ce3de9fe56525de0b498801
4 files changed