Fix canonicalize().

Fix canonicalize().

BUG=7075
R=rnystrom@google.com

Committed: https://code.google.com/p/dart/source/detail?r=22484

[Bob Nystrom, 2013-05-07 23:16:36]

LGTM.

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
File sdk/lib/_internal/pub/lib/src/io.dart (right):

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/io.dart:52: var seen = new Set<String>();
Wow. Nasty but at least it's very well documented.

If we are OK with pathos touching the file system, we might want to consider
moving this there.

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/io.dart:117: // beginning of the queue.
beginning -> end

[nweiz, 2013-05-07 23:19:14]

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
File sdk/lib/_internal/pub/lib/src/io.dart (right):

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/io.dart:52: var seen = new Set<String>();
On 2013/05/07 23:16:36, Bob Nystrom wrote:
> Wow. Nasty but at least it's very well documented.
> 
> If we are OK with pathos touching the file system, we might want to consider
> moving this there.

I thought about that, but right now pathos is very nicely isolated from anything
FS-related other than currentDirectory, and I like the idea of keeping it that
way. I think that'll pay dividends once we have configuration-specific
libraries.

https://codereview.chromium.org/15047005/diff/1/sdk/lib/_internal/pub/lib/src...
sdk/lib/_internal/pub/lib/src/io.dart:117: // beginning of the queue.
On 2013/05/07 23:16:36, Bob Nystrom wrote:
> beginning -> end

They're actually added to the beginning, since the pre-add contents of the queue
is components that will be beneath the target of the symlink.

[nweiz, 2013-05-07 23:19:29]

Committed patchset #1 manually as r22484 (presubmit successful).