dart2js cps: Track existence of try statements in resolution instead of traversing AST/IR nodes to …

dart2js cps: Track existence of try statements in resolution instead of traversing AST/IR nodes to check for it.

This change removes one traversal in the backend and it is one step in the direction of recording more inforamtion in resolution; the compuation of DartCapturedVariables, for example, could also be done during resolution and stored in the TreeElements.

The disadvantage is that resolution may look at more code than TypePropagation, but in this specific case I do not think that we are realisticly able to eliminate try statements in functions that are small enough to be inlined.

R=kmillikin@google.com

Committed: https://github.com/dart-lang/sdk/commit/4f8047af3bebc156bb1437e110f272d5a37987c0

[Kevin Millikin (Google), 2015-09-07 09:11:17]

lgtm

https://codereview.chromium.org/1311403003/diff/1/pkg/compiler/lib/src/cps_ir...
File pkg/compiler/lib/src/cps_ir/type_propagation.dart (right):

https://codereview.chromium.org/1311403003/diff/1/pkg/compiler/lib/src/cps_ir...
pkg/compiler/lib/src/cps_ir/type_propagation.dart:1854: if
(node.target.resolvedAst.elementd.containsTryStatement) return false;
Typo: elementd ==> elements.

https://codereview.chromium.org/1311403003/diff/1/pkg/compiler/lib/src/resolu...
File pkg/compiler/lib/src/resolution/members.dart (right):

https://codereview.chromium.org/1311403003/diff/1/pkg/compiler/lib/src/resolu...
pkg/compiler/lib/src/resolution/members.dart:4566: // TODO(karlklose): also
track the information about mutated variables, catch, and
I guess that's a long line.

[karlklose, 2015-09-08 09:08:25]

Committed patchset #1 (id:1) manually as
4f8047af3bebc156bb1437e110f272d5a37987c0 (presubmit successful).