make clear that invalidate just replaces with default

nikomatsakis · nikomatsakis · commit e35698371d36 · 2019-09-19T10:31:01.000-04:00
diff --git 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> {

Original file line number	Diff line number	Diff line change
`@@ -189,8 +189,7 @@ pub enum BreakableTarget {`
`189`	`189`
`190`	`190`	`impl CachedBlock {`
`191`	`191`	`fn invalidate(&mut self) {`
`192`		`- self.generator_drop = None;`
`193`		`- self.unwind = None;`
	`192`	`+ *self = CachedBlock::default();`
`194`	`193`	`}`
`195`	`194`
`196`	`195`	`fn get(&self, generator_drop: bool) -> Option<BasicBlock> {`