Fix issues in interpreter tests

Fix issues in interpreter tests

BUG=
R=asgerf@google.com

Committed: https://github.com/dart-lang/sdk/commit/13cb938bc749b9b693e8f577ca73918fbddcdf36

[zhivkag, 2017-05-02 09:19:09]

zhivkag@google.com changed reviewers:
+ asgerf@google.com, dmitryas@google.com

[zhivkag, 2017-05-02 09:19:10]

Hi, 

This changes fixes the issues reported by dart analyzer in strong mode in the
interpreter tests. It seems like there was a refactoring change in
front_end/src/fasta/testing/* which I didn't have locally and this resulted in
code with analyzer errors on master when it was merged. 
There should be no errors/warnings for test/interpreter now.

[asgerf, 2017-05-02 09:26:03]

https://codereview.chromium.org/2850413002/diff/1/pkg/kernel/test/interpreter...
File pkg/kernel/test/interpreter/suite.dart (right):

https://codereview.chromium.org/2850413002/diff/1/pkg/kernel/test/interpreter...
pkg/kernel/test/interpreter/suite.dart:61: bool strongMode =
environment.containsKey(STRONG_MODE);
The string " strong mode ", with spaces, is a key in the environment??

[zhivkag, 2017-05-02 09:39:53]

https://codereview.chromium.org/2850413002/diff/1/pkg/kernel/test/interpreter...
File pkg/kernel/test/interpreter/suite.dart (right):

https://codereview.chromium.org/2850413002/diff/1/pkg/kernel/test/interpreter...
pkg/kernel/test/interpreter/suite.dart:61: bool strongMode =
environment.containsKey(STRONG_MODE);
On 2017/05/02 09:26:03, asgerf wrote:
> The string " strong mode ", with spaces, is a key in the environment??

I think so, initially I passed false for strong mode for creating KernelTarget,
but since in CL below[1] this constant was introduced in test/closures, I made
the same change since I use the same FastaCompile step. 

[1]:
https://github.com/dart-lang/sdk/commit/06189b271a4a0bd87c469c33168279c68051c724

[asgerf, 2017-05-02 09:40:55]

Ok, lgtm

[zhivkag, 2017-05-02 09:43:41]

Description was changed from

==========
Fix issues in interpreter tests

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

to

==========
Fix issues in interpreter tests

BUG=
R=asgerf@google.com

Committed:
https://github.com/dart-lang/sdk/commit/13cb938bc749b9b693e8f577ca73918fbddcdf36
==========

[zhivkag, 2017-05-02 09:43:42]

Committed patchset #1 (id:1) manually as
13cb938bc749b9b693e8f577ca73918fbddcdf36 (presubmit successful).