tree de78f0066b2f359e5796de37268bdb4d3c99c075
parent 65bd67f45a5034e7194d98618840ca60e8c425c8
author Roberto Lublinerman <rluble@google.com> 1509067712 -0700
committer Roberto Lublinerman <rluble@google.com> 1509070934 -0700

Disable DataflowOptimizer by default and emit a warning when used.

DataflowOptimizer is problematic, it performs unsafe numerical
optimizations, has no guarantee of termination and is expensive
considering its small codesize impact. Most of the work done by
this pass is already performed by DeadCodeElimination.

Bug: #7854
Bug-Link: https://github.com/gwtproject/gwt/issues/7854
Change-Id: I66307f99548d0bbcdd0e5bd376db7173e918ae44