- Fix the external_test.dart as it was relying on outdated

- Fix the external_test.dart as it was relying on outdated
  functionality and broken syntax. So some tests were passing
  for the wrong reason.
- Fix the VM parser to properly report the compilation errors.
- Fix the generation of pretty names of private identifiers.

R=brianwilkerson@google.com

Committed: https://code.google.com/p/dart/source/detail?r=37208

[hausner, 2014-05-07 23:45:42]

I think the error messages are misleading or not precise enough.

https://codereview.chromium.org/269253007/diff/1/runtime/vm/parser.cc
File runtime/vm/parser.cc (right):

https://codereview.chromium.org/269253007/diff/1/runtime/vm/parser.cc#newcode...
runtime/vm/parser.cc:3201: "external method '%s' may not have field
initializers",
The message is a bit misleading. If the external message is a non-constructor,
the error should be caught at the same place where the parser checks that
non-constructor functions don't have a field initializer.

https://codereview.chromium.org/269253007/diff/1/runtime/vm/parser.cc#newcode...
runtime/vm/parser.cc:3281: "external method '%s' may not have a initializers",
If the external method is not a constructor, we should have reported this 3
lines above. This message should be more specific and say that external
constructors cannot contain initializers.

[Brian Wilkerson, 2014-05-08 14:22:54]

The test change LGTM. Thanks!

[Ivan Posva, 2014-06-10 22:01:48]

PTAL

Updated with even more tests and nicer error reporting.

-Ivan

[Brian Wilkerson, 2014-06-10 22:12:18]

LGTM

[Ivan Posva, 2014-06-10 22:19:41]

Committed patchset #2 manually as r37208 (presubmit successful).