Fix expression evaluation for resolving anonymous aggregrate types with a typedefed name

This fixes a recently reported a bug(https://llvm.org/bugs/show_bug.cgi?id=26790) relating to the clang expression evaluator no longer being able to resolve calls to
functions with arguments to typedefed anonymous structs, unions, or enums after a cleanup to the expression parsing code in r260768

This fixes the issue by attaching the tagged name to the original clang::TagDecl object when generating the typedef in lldb::ClangAstContext::CreateTypeDef.

This also fixes the issue for anonymous typedefs for non-struct types (unions and enums) where we have a tag name.


Author: Luke Drummond <luke.drummond@codeplay.com>
Differential Revision: http://reviews.llvm.org/D18099

llvm-svn: 263544