Rollup of 8 pull requests#83843

Closed

GuillaumeGomez wants to merge 19 commits intorust-lang:masterfrom

GuillaumeGomez:rollup-4iy5ytf

Commits on Mar 3, 2021

BTree: move blocks around in node.rs
ssomers
committed

Commits on Mar 22, 2021

Add `download-rustc = "if-unchanged"`
jyn514
committed

Commits on Mar 24, 2021

Fix error codes check run and ensure it will not go unnoticed again
GuillaumeGomez
committed

Commits on Mar 26, 2021

Fix compiletest on FreeBSD
asomers
committed

Commits on Apr 2, 2021

rustdoc: highlight macros more efficiently
notriddle
committed

Commits on Apr 4, 2021