From e35698371d36da83d3aca8322ad812fa5512b90f Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Thu, 19 Sep 2019 10:30:46 -0400
Subject: [PATCH] make clear that `invalidate` just replaces with `default`

---
 src/librustc_mir/build/scope.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/librustc_mir/build/scope.rs b/src/librustc_mir/build/scope.rs
index 3c735c8cb09..9c1acb3faae 100644
--- a/src/librustc_mir/build/scope.rs
+++ b/src/librustc_mir/build/scope.rs
@@ -189,8 +189,7 @@ pub enum BreakableTarget {
 
 impl CachedBlock {
     fn invalidate(&mut self) {
-        self.generator_drop = None;
-        self.unwind = None;
+        *self = CachedBlock::default();
     }
 
     fn get(&self, generator_drop: bool) -> Option<BasicBlock> {