Revert "Move all inlining work to translateRegion()"

Summary: This reverts commit 7a17649306b003c961a86e9e33b5bb92e979192e.

Perflab says it broke lots of things.

Reviewed By: @jdelong

Differential Revision: D1709049

Signature: t1:1709049:1417208800:3f72a2a4d47968d7db9ae906c71ab28c54929041