We use the HTML ID of a member element to get its name. If there are
multiple members with the same type and name (e. g. from a Deref
implementation), the ID has a suffix to make it unique. Previosuly, we
just interpreted this suffix as part of the name. With this patch, we
strip the suffix and only use the actual name.
This patch refactors the test suite:
- Instead of always generating the documentation with the available
rustdoc version, we now store generated documentation for all
supported rustdoc versions in the test/html directory.
- Instead of using one snapshot per test case, we now use one snapshot
per test case and rustdoc version.
