Revert "JIT: Separate code allocation and initialization."

This reverts commit e1b36f09cb478a39ba443f6acb11cd1901c01c1d.

Reason for revert: Crashes in art::jit::JitMemoryRegion::FreeCode
https://logs.chromium.org/logs/art/buildbucket/cr-buildbucket.appspot.com/8900060997388741808/+/steps/test_libcore/0/stdout

Change-Id: I40259baec9acbb7889732548f8b31e0a48651cd9
6 files changed