Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern.""

Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern.""

This reverts commit 890f694de5fecdda128851ded06ea40ecd3c6c07.

Previous commit was passing field_type_map_ down in a place where it was not passed down before.

This caused some handles to be used across zones, which caused crashes.

BUG=

Committed: https://github.com/dart-lang/sdk/commit/e495e100dd8ec132b5e2f971ba79ef3e4f0896e5

[Vyacheslav Egorov (Google), 2016-10-26 08:36:36]

vegorov@google.com changed reviewers:
+ fschneider@google.com, rmacnak@google.com

[Vyacheslav Egorov (Google), 2016-10-26 08:36:36]

I have fixed the issue with precompiler that caused revert.

The issue was in Precompiler::ProcessFunction where we were previously passing
down NULL field type map, but after my change we started getting non-NULL one. I
restored the old behavior.

PTAL

[Vyacheslav Egorov (Google), 2016-10-26 10:25:51]

Description was changed from

==========
Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern.""

This reverts commit 890f694de5fecdda128851ded06ea40ecd3c6c07.

Previous commit was passing field_type_map_ down in a place where it was not
passed down before.

This caused some handles to be used across zones, which caused crashes.

BUG=
==========

to

==========
Revert "Revert "Recognize and optimize a.runtimeType == b.runtimeType pattern.""

This reverts commit 890f694de5fecdda128851ded06ea40ecd3c6c07.

Previous commit was passing field_type_map_ down in a place where it was not
passed down before.

This caused some handles to be used across zones, which caused crashes.

BUG=

Committed:
https://github.com/dart-lang/sdk/commit/e495e100dd8ec132b5e2f971ba79ef3e4f0896e5
==========

[Vyacheslav Egorov (Google), 2016-10-26 10:25:52]

Committed patchset #1 (id:1) manually as
e495e100dd8ec132b5e2f971ba79ef3e4f0896e5 (presubmit successful).