Small fixes to top level type inference.

Small fixes to top level type inference.

This CL makes two fixes:

1. When a field is visited for the second time (to infer
subexpressions), don't use the inferred field type as the context;
this can change the inference results in a few rare circumstances,
making it different from what would be inferred inside a method body.

2. When doing extended top level type inference is enabled, only skip
subexpressions whose type is not needed.

Note that some tests had to be moved (either partially or completely)
into pkg/front_end/testcases/inference_new to reflect the fact that
front_end type inference now produces more correct results than
analyzer.  Also, the annotation comments in
pkg/front_end/testcases/inference_new/dependency_only_if_generic_method.dart
were completely bogus and needed to be changed.

R=ahe@google.com

Committed: https://github.com/dart-lang/sdk/commit/20c25f5cfc3e07e03b1718bc4865f3c1a0f14dc8

[Paul Berry, 2017-06-23 03:44:02]

paulberry@google.com changed reviewers:
+ sigmund@google.com

[ahe, 2017-06-23 12:42:15]

ahe@google.com changed reviewers:
+ ahe@google.com

[ahe, 2017-06-23 12:42:15]

lgtm

[Paul Berry, 2017-06-23 17:48:02]

Description was changed from

==========
Small fixes to top level type inference.

This CL makes two fixes:

1. When a field is visited for the second time (to infer
subexpressions), don't use the inferred field type as the context;
this can change the inference results in a few rare circumstances,
making it different from what would be inferred inside a method body.

2. When doing extended top level type inference is enabled, only skip
subexpressions whose type is not needed.

Note that some tests had to be moved (either partially or completely)
into pkg/front_end/testcases/inference_new to reflect the fact that
front_end type inference now produces more correct results than
analyzer.  Also, the annotation comments in
pkg/front_end/testcases/inference_new/dependency_only_if_generic_method.dart
were completely bogus and needed to be changed.
==========

to

==========
Small fixes to top level type inference.

This CL makes two fixes:

1. When a field is visited for the second time (to infer
subexpressions), don't use the inferred field type as the context;
this can change the inference results in a few rare circumstances,
making it different from what would be inferred inside a method body.

2. When doing extended top level type inference is enabled, only skip
subexpressions whose type is not needed.

Note that some tests had to be moved (either partially or completely)
into pkg/front_end/testcases/inference_new to reflect the fact that
front_end type inference now produces more correct results than
analyzer.  Also, the annotation comments in
pkg/front_end/testcases/inference_new/dependency_only_if_generic_method.dart
were completely bogus and needed to be changed.

R=ahe@google.com

Committed:
https://github.com/dart-lang/sdk/commit/20c25f5cfc3e07e03b1718bc4865f3c1a0f14dc8
==========

[Paul Berry, 2017-06-23 17:48:04]

Committed patchset #1 (id:1) manually as
20c25f5cfc3e07e03b1718bc4865f3c1a0f14dc8 (presubmit successful).