several tests failing with ICEs

[nrc]

failures:
    test::test_bin_lib_project
    test::test_find_all_refs
    test::test_multiple_binaries

[nrc]

backtrace:

  10: <rustc_save_analysis::dump_visitor::DumpVisitor<'l, 'tcx, 'll, D> as syntax::visit::Visitor<'l>>::visit_expr
  11: <rustc_save_analysis::dump_visitor::DumpVisitor<'l, 'tcx, 'll, D> as syntax::visit::Visitor<'l>>::visit_local
  12: <rustc_save_analysis::dump_visitor::DumpVisitor<'l, 'tcx, 'll, D>>::nest_tables
  13: <rustc_save_analysis::dump_visitor::DumpVisitor<'l, 'tcx, 'll, D> as syntax::visit::Visitor<'l>>::visit_item
  14: <rustc_save_analysis::dump_visitor::DumpVisitor<'l, 'tcx, 'll, D> as syntax::visit::Visitor<'l>>::visit_mod
  15: <rustc_save_analysis::CallbackHandler<'b> as rustc_save_analysis::SaveHandler>::save
  16: rustc_save_analysis::process_crate
             at /checkout/src/librustc_save_analysis/lib.rs:1017
  17: <rls::build::BuildQueue::rustc::RlsRustcCalls as rustc_driver::CompilerCalls<'a>>::build_controller::{{closure}}
             at src/build.rs:590
  18: rustc_driver::driver::compile_input::{{closure}}
  19: rustc_driver::driver::phase_3_run_analysis_passes::{{closure}}
  20: rustc_driver::driver::phase_3_run_analysis_passes
  21: rustc_driver::driver::compile_input
  22: rustc_driver::run_compiler
  23: rls::build::BuildQueue::rustc::{{closure}}::{{closure}}
             at src/build.rs:500
  24: rustc_driver::run::{{closure}}
             at /checkout/src/librustc_driver/lib.rs:130
  25: rustc_driver::monitor::{{closure}}
             at /checkout/src/librustc_driver/lib.rs:1082

[Xanewok]

test_multiple_binaries fails intermittently since 75e466f, probably because of a config race -
sometimes it returns analysis for default crate, sometimes for the one specified in rls.toml.

[nrc]

nice catch on the config issue. I don't think it is quite right - we don't look at rls.toml at all now (I removed the code that can even do it). So, it must need cofiguration in the test, but I'm not sure why that would lead to intermittent failure.

[nrc]

FIxed other than stuff tracked in #404