This CL is identical to the reverted CL 2990703002 which implements
syntactic support for generalized void in the analyzer, plus two bug
fixes in pkg/analyzer/test/generated/parser_test.dart and
pkg/analyzer_cli/test/error_test.dart. In the former, a test on parsing
`void,` was changed to expect an error: _isTypeIdentifier on a lone
`void` will no longer return true, which is necessary because `void`
can now be used as a type annotation alone. Another test on `void x`
was added, which produces the behavior previously seen for `void,`.
In error_test, the error which is used throughout was changed from
`void foo;` to `var int foo;` (because the former is no longer an
error).
Review-Url: https://codereview.chromium.org/2992623002 .
Erik Ernst