dart2js: strengthen loop condition in loop body

dart2js: strengthen loop condition in loop body

Just a few improvements in a huge app, e.g.

      for (; node != null;)
        if (node == null ? element == null : node === element)
          return true;
        else
          node = node.parentElement;
--->
      for (; node != null;)
        if (node === element)
          return true;
        else
          node = node.parentElement;

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/64ab012f2a77b2709c250bacc9246b5c3949896c

[sra1, 2017-04-28 02:15:25]

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

[Siggi Cherem (dart-lang), 2017-04-28 22:17:13]

lgtm

[sra1, 2017-04-28 23:19:51]

Description was changed from

==========
dart2js: strengthen loop condition in loop body

Just a few improvements in a huge app, e.g.

      for (; node != null;)
        if (node == null ? element == null : node === element)
          return true;
        else
          node = node.parentElement;
--->
      for (; node != null;)
        if (node === element)
          return true;
        else
          node = node.parentElement;
==========

to

==========
dart2js: strengthen loop condition in loop body

Just a few improvements in a huge app, e.g.

      for (; node != null;)
        if (node == null ? element == null : node === element)
          return true;
        else
          node = node.parentElement;
--->
      for (; node != null;)
        if (node === element)
          return true;
        else
          node = node.parentElement;

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/64ab012f2a77b2709c250bacc9246b5c3949896c
==========

[sra1, 2017-04-28 23:19:52]

Committed patchset #2 (id:20001) manually as
64ab012f2a77b2709c250bacc9246b5c3949896c (presubmit successful).