Fix for switch type inferrence

Fix for switch type inferrence

Committed: https://code.google.com/p/dart/source/detail?r=26022

[sra1, 2013-08-10 02:01:39]

https://codereview.chromium.org/22279006/diff/1/sdk/lib/_internal/compiler/im...
File sdk/lib/_internal/compiler/implementation/types/inferrer_visitor.dart
(left):

https://codereview.chromium.org/22279006/diff/1/sdk/lib/_internal/compiler/im...
sdk/lib/_internal/compiler/implementation/types/inferrer_visitor.dart:981: //
[locals] for the join block.
However, we don't want seenReturnOrThrow to stick.

https://codereview.chromium.org/22279006/diff/1/sdk/lib/_internal/compiler/im...
File sdk/lib/_internal/compiler/implementation/types/inferrer_visitor.dart
(right):

https://codereview.chromium.org/22279006/diff/1/sdk/lib/_internal/compiler/im...
sdk/lib/_internal/compiler/implementation/types/inferrer_visitor.dart:993: //
switch is dead code.
I don't understand the above comment.  Does it apply only with the
'optimization' that I just removed?

[sra1, 2013-08-12 17:49:48]

I've added a test.
Still have some reservations about the fix (see initial comments).

Since the issue has been reported as blocking by multiple customers, I will TBR
if I don't hear anything.

[sra1, 2013-08-12 19:04:36]

Committed patchset #2 manually as r26022 (presubmit successful).

[ngeoffray, 2013-08-13 12:03:35]

LGTM! Thanks for the fix Stephen. I have an updated version here:

https://codereview.chromium.org/23050002