librustc: De-`@mut` the additional library search paths
librustc: De-`@mut` arrays of `entry` used in the encoder
librustc: De-`@mut` `Module::import_resolutions`
librustc: De-`@mut` several instances of `io::Writer`.

There are a few more related to pretty printing.
librustc: De-`@mut` the bindings list in pattern resolution
librustc: De-`@mut` `Module::children`
librustc: Remove the unused `reported` table from the loan checking pass
librustc: De-`@mut` `ScopeInfo::cleanups`
librustc: De-`@mut` `ScopeInfo::cleanup_paths`
librustc: De-`@mut` `ScopeInfo::landing_pad`
librustc: De-`@mut` `ScopeInfo`
librustc: De-`@mut` the various glues in the type descriptor info
librustc: De-`@mut` the type descriptor info
librustc: De-`@mut` `creader::Env`
librustc: De-`@mut` the method map
librustc: De-`@mut` the moves map
librustc: De-`@mut` `impl_dups` in method checking
librustc: De-`@mut` `TestCtxt::path`
librustc: De-`@mut` `TestCtxt::testfns`
librustc: De-`@mut` the test context