Add support for ignoring a string after the native keyword in a method, needed for compatability ...

Add support for ignoring a string after the native keyword in a method, needed for compatability with frog
Committed: https://code.google.com/p/dart/source/detail?r=2029

[Brian Wilkerson, 2011-12-01 23:18:48]

We want to make dartc tolerant of the frog code so that the Seattle team can use
the Editor and give us some feedback, but it isn't necessary to compile the code
correctly. (They'll run it though frog before executing it.)

One test failed on my local machine with a stack overflow, but I suspect that
I'm just having trouble getting my machine set up correctly to run the tests.
I'm fine, though, with holding off on this CL until I can get the problem fixed;
I'd rather do that than break the build.

[Brian Wilkerson, 2011-12-02 17:34:21]

I was able to get the tests to pass this morning. PTAL.

[mmendez, 2011-12-02 18:54:37]

On 2011/12/02 17:34:21, Brian Wilkerson wrote:
> I was able to get the tests to pass this morning. PTAL.

LGTM

[Bill Hesse, 2011-12-05 12:27:54]

I'm still getting an error on the runtime/bin files:

http://codereview.chromium.org/8769023/diff/1/compiler/java/com/google/dart/c...
File compiler/java/com/google/dart/compiler/parser/DartParser.java (right):

http://codereview.chromium.org/8769023/diff/1/compiler/java/com/google/dart/c...
compiler/java/com/google/dart/compiler/parser/DartParser.java:1118:
reportError(position(), ParserErrorCode.EXPORTED_FUNCTIONS_MUST_BE_STATIC);
This error, exported functions must be static, is hit by
runtime/bin/directory_impl.dart, since it has a private method of a private
class implemented with a native C++ function.  You can see this by creating a
file:
#library("bill");
#source("runtime/bin/directory_impl.dart");
and opening it in the editor.

Why does this assume that native blocks are only on exported functions?

[Brian Wilkerson, 2011-12-05 17:18:34]

> Why does this assume that native blocks are only on exported functions?

I don't know, but that's not the bug this CL was intended to fix. That's
pre-existing behavior that I didn't change. Perhaps you could add an issue for
dartc to track this problem.