[lldb] Reference STL types in import-std-module tests

With the recent patches to the ASTImporter that improve template type importing
(D87444), most of the import-std-module tests can now finally import the
type of the STL container they are testing. This patch removes most of the casts
that were added to simplify types to something the ASTImporter can import
(for example, std::vector<int>::size_type was casted to `size_t` until now).
Also adds the missing tests that require referencing the container type (for
example simply printing the whole container) as here we couldn't use a casting
workaround.

The only casts that remain are in the forward_list tests that reference
the iterator and the stack test. Both tests are still failing to import the
respective container type correctly (or crash while trying to import).

0 files changed, 0 insertions, 0 deletions