Rollup merge of rust-lang#89142 - nerandell:master, r=jackh726

the8472 · web-flow · commit aca790b3d627 · 2021-09-21T22:54:07.000+02:00
Fix match for placeholder region cc rust-lang#89118
diff --git a/compiler/rustc_middle/src/ich/impls_ty.rs b/compiler/rustc_middle/src/ich/impls_ty.rs
@@ -90,7 +90,10 @@ impl<'a> HashStable<StableHashingContext<'a>> for ty::RegionKind {
             ty::ReFree(ref free_region) => {
                 free_region.hash_stable(hcx, hasher);
             }
-            ty::ReVar(..) | ty::RePlaceholder(..) => {
+            ty::RePlaceholder(p) => {
+                p.hash_stable(hcx, hasher);
+            }
+            ty::ReVar(..) => {
                 bug!("StableHasher: unexpected region {:?}", *self)
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -90,7 +90,10 @@ impl<'a> HashStable<StableHashingContext<'a>> for ty::RegionKind {`
`90`	`90`	`ty::ReFree(ref free_region) => {`
`91`	`91`	`free_region.hash_stable(hcx, hasher);`
`92`	`92`	`}`
`93`		`- ty::ReVar(..) \| ty::RePlaceholder(..) => {`
	`93`	`+ ty::RePlaceholder(p) => {`
	`94`	`+ p.hash_stable(hcx, hasher);`
	`95`	`+ }`
	`96`	`+ ty::ReVar(..) => {`
`94`	`97`	`bug!("StableHasher: unexpected region {:?}", *self)`
`95`	`98`	`}`
`96`	`99`	`}`