Add basic checks for well-formedness of `fn`/`fn_mut` lang items#86246

Merged

bors merged 2 commits intorust-lang:masterfrom

FabianWolff:issue-83471

Sep 25, 2021

Commits on Sep 24, 2021

Add basic checks for well-formedness of `fn`/`fn_mut` lang items
FabianWolff
committed
Make error message for malformed `fn`/`fn_mut` lang item more specific
FabianWolff
committed