Instead of finding aux-build files in `auxiliary`, we now search for an
`aux` directory relative to the test. So if your test is
`compile-fail/foo.rs`, we would look in `compile-fail/aux`. Similarly,
we ignore the `aux` directory when searching for tets.
syntax: Merge PathParsingMode::NoTypesAllowed and PathParsingMode::ImportPrefix
syntax: Rename PathParsingMode and its variants to better express their purpose
syntax: Remove obsolete error message about 'self lifetime
syntax: Remove ALLOW_MODULE_PATHS workaround
syntax/resolve: Adjust some error messages
resolve: Compare unhygienic (not renamed) names with keywords::Invalid, invalid identifiers may appear to be valid after renaming
