Allow using the JIT

Instead of the JIT only being available for eng builds [or configurable
via environment variable], allow the JIT to be enabled programatically.

(cherry picked from commit 12434f8cce66a753ef49c07b503f9625e01366c8)

Change-Id: Id3c5ae227ed400e489bb723a56c516dfc12acd89
2 files changed