Initializing a final instance is a runtime error

Initializing a final instance is a runtime error

If a final instance variable is initialized at the point of declaration, it
is a runtime error if it is initialized again in a constructor’s initializer
list or by an initializing formal.

If any instance field is initialized more than once in the initializer list of
a constructor, or by an initializing formal parameter, it is a compile time
error.

Adding a new test to cover the expected runtime error.

Fixes issue 13335.

R=regis@google.com

Committed: https://code.google.com/p/dart/source/detail?r=39562

[hausner, 2014-08-26 00:11:15]

hausner@google.com changed reviewers:
+ regis@google.com

[hausner, 2014-08-26 01:02:00]

There are some status file updates still missing in this CL.

[regis, 2014-08-26 15:37:20]

LGTM

[hausner, 2014-08-26 19:37:45]

Committed patchset #2 manually as r39562 (presubmit successful).