typedef error messages desugar incorrectly

[lenary]

If you have a typedef used in a written type, which desugars to a ptr<T> or array_ptr<T> type, when the error printer desugars the typedef type, it prints it as T *, which can be confusing.

Here is a not-very-confusing example:

/Users/ashe2/Code/checkedc-llvm-test-suite/MultiSource/Benchmarks/Olden/em3d/make_graph.c:357:19: error: assigning to
      '_Array_ptr<_Ptr<node_t>>' (aka 'struct node_t **') from incompatible type 'table_arr_t'
      (aka 'struct table_arr_t')

However, I've seen examples where I've tried assigning into a ptr<T> from a T * and you get an error message that says error: assigning to '_Array_ptr<Node>' (aka 'struct node_t *') from incompatible type 'Node *' (aka 'struct node_t **') which is a lot more confusing.

[dtarditi]

This is fixed.