dart2js: Keep refined type for type checks

dart2js: Keep refined type for type checks

The generated code for inserted receiver and argument type checks
depends on the input type.  Keeping the type after removing HTypeKnown
refinements give better code.

In a large app, 58% of the 'int' tests are replaced with cheaper 'num'
tests on the basis of the more precise input type.

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/435da5d44bbab17b5c6acfade591e984fa22034f

[sra1, 2017-02-03 21:39:26]

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

[Siggi Cherem (dart-lang), 2017-02-03 21:48:17]

lgtm

https://codereview.chromium.org/2674813004/diff/1/pkg/compiler/lib/src/ssa/co...
File pkg/compiler/lib/src/ssa/codegen.dart (right):

https://codereview.chromium.org/2674813004/diff/1/pkg/compiler/lib/src/ssa/co...
pkg/compiler/lib/src/ssa/codegen.dart:2820: isIntCheck &&
inputType.nonNullable().containsOnlyInt(closedWorld);
I think it's fine to keep it nullable here (the answer is the same I believe)

[sra1, 2017-02-04 00:33:47]

Description was changed from

==========
dart2js: Keep refined type for type checks

The generated code for inserted receiver and argument type checks
depends on the input type.  Keeping the type after removing HTypeKnown
refinements give better code.

In a large app, 58% of the 'int' tests are replaced with cheaper 'num'
tests on the basis of the more precise input type.
==========

to

==========
dart2js: Keep refined type for type checks

The generated code for inserted receiver and argument type checks
depends on the input type.  Keeping the type after removing HTypeKnown
refinements give better code.

In a large app, 58% of the 'int' tests are replaced with cheaper 'num'
tests on the basis of the more precise input type.

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/435da5d44bbab17b5c6acfade591e984fa22034f
==========

[sra1, 2017-02-04 00:33:48]

Committed patchset #1 (id:1) manually as
435da5d44bbab17b5c6acfade591e984fa22034f (presubmit successful).