Rollup of 6 pull requests#67451

Closed

Centril wants to merge 21 commits intorust-lang:masterfrom

Centril:rollup-4f1zxxc

Commits on Dec 6, 2019

Fix pointing at arg when cause is outside of call
VirrageS
committed

Commits on Dec 7, 2019

Rename tests and add short test description
VirrageS
committed

Commits on Dec 13, 2019

Update tokio crates to latest versions
mati865
committed

Commits on Dec 15, 2019

Commits on Dec 16, 2019

Fix handling of wasm import modules and names
alexcrichton
committed

Commits on Dec 18, 2019

Commits on Dec 20, 2019