Auto merge of #2466 - jtgeibel:update/inventory, r=JohnTitor

Fix tests when linking with lld

This bumps a few dependencies (in particular `ctor`) to fix linking with `lld`.  Before this fix, tests would fail because the background jobs were not being registered correctly.

I'm seeing very promising results with `lld` locally.  Here are my times for a clean incremental build (after `touch src/lib.rs`) when running `time cargo test --no-run`:

### Ubuntu 20.04 default linker

```
real    0m54.108s
user    4m57.944s
sys     0m50.454s
```

### With `RUSTFLAGS="-C link-arg=-fuse-ld=lld"`

```
real    0m20.015s
user    0m59.601s
sys     0m14.471s
```

Our production and CI are on an Ubuntu 16.04 stack, so I'm not sure what it would take to make this configuration the default.

r? @JohnTitor

Author: bors