dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that it is idempotent for that input. Most passes
are not yet idempotent, but this utility should help us get there.

BUG=

Committed: https://github.com/dart-lang/sdk/commit/6c9a7ec96717666b50a669c84502f29bb5496896

[asgerf, 2016-01-21 04:16:58]

Description was changed from

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

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

to

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that its result was idempotent. Most passes are
not yet idempotent, but this utility should help us get there.

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

[asgerf, 2016-01-21 04:17:25]

Description was changed from

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that its result was idempotent. Most passes are
not yet idempotent, but this utility should help us get there.

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

to

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that it is idempotent for that input. Most passes
are not yet idempotent, but this utility should help us get there.

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

[asgerf, 2016-01-21 04:18:15]

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

[Kevin Millikin (Google), 2016-01-26 08:40:40]

LVGTM.

[asgerf, 2016-01-26 15:37:35]

Description was changed from

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that it is idempotent for that input. Most passes
are not yet idempotent, but this utility should help us get there.

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

to

==========
dart2js cps: Debugging utility and fix idempotency in shrinking reducer.

Shrinking reductions would miss some redexes that were created during
a reduction.  It now finds more redexes and has a self-checking mode
that can be enabled when working on the pass.

Also adds some general debugging utility functions to the CPS IR.

The root class Node now has "debugString" and "debugPrint" methods for
conveniently getting its SExpression.

The CpsFunctionCompiler now has a method "debugCpsPass" which runs
a CPS pass while checking that it is idempotent for that input. Most passes
are not yet idempotent, but this utility should help us get there.

BUG=

Committed:
https://github.com/dart-lang/sdk/commit/6c9a7ec96717666b50a669c84502f29bb5496896
==========

[asgerf, 2016-01-26 15:37:36]

Committed patchset #5 (id:80001) manually as
6c9a7ec96717666b50a669c84502f29bb5496896 (presubmit successful).