DeclaratorDecl contains a DeclaratorInfo* to keep type source info.
Subclasses of DeclaratorDecl are FieldDecl, FunctionDecl, and VarDecl.
EnumConstantDecl still inherits from ValueDecl since it has no need for DeclaratorInfo.

Decl/Sema interfaces accept a DeclaratorInfo as parameter but no DeclaratorInfo is created yet.

llvm-svn: 79392