Rollup of 8 pull requests#83905

Merged

bors merged 22 commits intorust-lang:masterfrom

JohnTitor:rollup-pa1la80

Apr 6, 2021

Commits on Apr 1, 2021

Catch a bad placeholder type error for statics in `extern`s
JohnTitor
committed

Commits on Apr 2, 2021

Commits on Apr 3, 2021

expand: Do not ICE when a legacy AST-based macro attribute produces and empty expression
petrochenkov
committed

Commits on Apr 4, 2021

Commits on Apr 5, 2021