* features/code_check/W0704.feature : Add scenario to reproduce a parse
  error when the enumerator name is conflicting with the prior typedef
  name.
* MANIFEST : Ditto.

* lib/adlint/cc1/lexer.rb : Rewrite identifier set to track declared
  identifiers in preparation for fixing incomplete identifier to typedef
  name translation.

* lib/adlint/cc1/parser.y : Fix incomplete identifier to typedef name
  translation when the declaring enumerator name is conflicting with the
  prior typedef name.