Implemented support for generalized void in analyzer.

Implemented support for generalized void in analyzer.

Changed the analyzer parser to accept usages of `void` which were
previously rejected as syntax errors: `void` can now be the type
annotation for a variable or parameter, and it can be an actual type
argument.

Removed affected error codes like VOID_PARAMETER, VOID_VARIABLE,
VOID_RETURN_FOR_GETTER and associated declarations (like checking
functions), and adjusted test cases to expect success rather than
compile time errors.

Adjusted generalized_void_syntax_test.dart (it had real errors like
`final` variables with no initializer etc. that were not detected
when tools would just reject the file as syntactically wrong).

R=brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/1d44f5296a711c5f60c99a525db1458014c3fe41

[eernst, 2017-07-26 10:05:58]

eernst@google.com changed reviewers:
+ brianwilkerson@google.com

[Brian Wilkerson, 2017-07-26 14:21:59]

lgtm

[eernst, 2017-07-26 15:45:16]

Description was changed from

==========
Implemented support for generalized void in analyzer.

Changed the analyzer parser to accept usages of `void` which were
previously rejected as syntax errors: `void` can now be the type
annotation for a variable or parameter, and it can be an actual type
argument.

Removed affected error codes like VOID_PARAMETER, VOID_VARIABLE,
VOID_RETURN_FOR_GETTER and associated declarations (like checking
functions), and adjusted test cases to expect success rather than
compile time errors.

Adjusted generalized_void_syntax_test.dart (it had real errors like
`final` variables with no initializer etc. that were not detected
when tools would just reject the file as syntactically wrong).
==========

to

==========
Implemented support for generalized void in analyzer.

Changed the analyzer parser to accept usages of `void` which were
previously rejected as syntax errors: `void` can now be the type
annotation for a variable or parameter, and it can be an actual type
argument.

Removed affected error codes like VOID_PARAMETER, VOID_VARIABLE,
VOID_RETURN_FOR_GETTER and associated declarations (like checking
functions), and adjusted test cases to expect success rather than
compile time errors.

Adjusted generalized_void_syntax_test.dart (it had real errors like
`final` variables with no initializer etc. that were not detected
when tools would just reject the file as syntactically wrong).

R=brianwilkerson@google.com

Committed:
https://github.com/dart-lang/sdk/commit/1d44f5296a711c5f60c99a525db1458014c3fe41
==========

[eernst, 2017-07-26 15:45:18]

Committed patchset #2 (id:20001) manually as
1d44f5296a711c5f60c99a525db1458014c3fe41 (presubmit successful).