Merge 2.10

Intermediate steps:

```
g merge -s ours e350bd2 2bfe0e7
g merge 25bcba5
g merge -s ours 50c8b39
g merge 075f6f2 e09a8a2
g merge 6045a05 # update check file for presentation/completion-implicit-chained
g merge -s ours 2.10.x
 ```