Revert accidental comment deletion · rust-lang/rust@d902179

Original file line number	Diff line number	Diff line change
`@@ -821,6 +821,8 @@ impl<'a, 'mir, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'mir, 'tcx, R>`
`821`	`821`	`\| TerminatorKind::Return`
`822`	`822`	`\| TerminatorKind::TailCall { .. }`
`823`	`823`	`\| TerminatorKind::CoroutineDrop => {`
	`824`	`+// Returning from the function implicitly kills storage for all locals and statics.`
	`825`	`+// Often, the storage will already have been killed by an explicit`
`824`	`826`	`// StorageDead, but we don't always emit those (notably on unwind paths),`
`825`	`827`	`// so this "extra check" serves as a kind of backup.`
`826`	`828`	`let borrow_set = self.borrow_set.clone();`