Handle assert with message in type inference

Handle assert with message in type inference

Closes #27882

R=sra@google.com

Committed: https://github.com/dart-lang/sdk/commit/bf13fc1b287125252a5d8c41b03b5b353c79fb25

[Johnni Winther, 2016-11-25 13:41:08]

johnniwinther@google.com changed reviewers:
+ sra@google.com

[sra1, 2016-11-26 22:41:20]

https://codereview.chromium.org/2528043003/diff/1/tests/compiler/dart2js/asse...
File tests/compiler/dart2js/assert_message_throw_test.dart (right):

https://codereview.chromium.org/2528043003/diff/1/tests/compiler/dart2js/asse...
tests/compiler/dart2js/assert_message_throw_test.dart:12: var list = [];
I don't understand what this is testing.

Perhaps do something like

var a;
assert(true, (a="Hi"));
var b = a;

b should be inferred as String

[Johnni Winther, 2016-11-28 10:08:29]

https://codereview.chromium.org/2528043003/diff/1/tests/compiler/dart2js/asse...
File tests/compiler/dart2js/assert_message_throw_test.dart (right):

https://codereview.chromium.org/2528043003/diff/1/tests/compiler/dart2js/asse...
tests/compiler/dart2js/assert_message_throw_test.dart:12: var list = [];
On 2016/11/26 22:41:20, sra1 wrote:
> I don't understand what this is testing.
> 
> Perhaps do something like
> 
> var a;
> assert(true, (a="Hi"));
> var b = a;
> 
> b should be inferred as String

The crash reported in #27882. We had inconsistent reasoning on reachable because
we assumed that `throw "unreachable"` always happened. Later code would still
try to access the type info for `list` and crash.

Added more tests.

[sra1, 2016-11-28 20:07:50]

LGTM.
Thanks!

[Johnni Winther, 2016-11-29 07:36:44]

Description was changed from

==========
Handle assert with message in type inference

Closes #27882
==========

to

==========
Handle assert with message in type inference

Closes #27882

R=sra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/bf13fc1b287125252a5d8c41b03b5b353c79fb25
==========

[Johnni Winther, 2016-11-29 07:36:45]

Committed patchset #2 (id:20001) manually as
bf13fc1b287125252a5d8c41b03b5b353c79fb25 (presubmit successful).