Add --verify-ir flag to dartk and test.py.

Add --verify-ir flag to dartk and test.py.

This replaces the old --sanity-check flag from dartk. Some files have
been renamed to avoid the wording "sanity check".

Compared to --sanity-check, the following checks have been added:
- variables are not referenced out of scope
- variables are not redeclared
- class type parameters are not referenced from static context

A unit test has been added to check that the verifier rejects certain
invalid ASTs.

BUG=
R=kmillikin@google.com

Committed: https://github.com/dart-lang/sdk/commit/8f124898398cee6b147290bddcec722e76e93dbe

[asgerf, 2016-11-25 15:37:51]

asgerf@google.com changed reviewers:
+ ahe@google.com, kmillikin@google.com

[asgerf, 2016-11-25 15:37:52]

--verify-ir adds ~20 seconds to testing (5:55 -> 6:15) so I did not want to
enable it by default. We'll probably want to add more checks, which might also
slow it down further.

[Kevin Millikin (Google), 2016-11-28 11:14:04]

LGTM.

[asgerf, 2016-11-28 11:21:23]

Description was changed from

==========
Add --verify-ir flag to dartk and test.py.

This replaces the old --sanity-check flag from dartk. Some files have
been renamed to avoid the wording "sanity check".

Compared to --sanity-check, the following checks have been added:
- variables are not referenced out of scope
- variables are not redeclared
- class type parameters are not referenced from static context

A unit test has been added to check that the verifier rejects certain
invalid ASTs.

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

to

==========
Add --verify-ir flag to dartk and test.py.

This replaces the old --sanity-check flag from dartk. Some files have
been renamed to avoid the wording "sanity check".

Compared to --sanity-check, the following checks have been added:
- variables are not referenced out of scope
- variables are not redeclared
- class type parameters are not referenced from static context

A unit test has been added to check that the verifier rejects certain
invalid ASTs.

BUG=
R=kmillikin@google.com

Committed:
https://github.com/dart-lang/sdk/commit/8f124898398cee6b147290bddcec722e76e93dbe
==========

[asgerf, 2016-11-28 11:21:25]

Committed patchset #2 (id:20001) manually as
8f124898398cee6b147290bddcec722e76e93dbe (presubmit successful).