This patch adds tests for Rust 1.50.0 which we can mostly copy from
1.49.0. There is only a small change to the abbreviated descriptions in
the search index and to edition-specific code.
With Rust 1.48.0, support for link shorthands, i. e. `[Test]` instead of
`[Test][]`, was added. Therefore, some of the links are now rendered
correctly. Otherwise we can just copy the snapshots and don’t need any
code changes.
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.
Robin Krahl