Don't require visit_body to take a lifetime that must outlive the function call

compiler/rustc_hir/src/intravisit.rs

@@ -299,7 +299,7 @@ pub trait Visitor<'v>: Sized {
         walk_item(self, i)
     }
 
-    fn visit_body(&mut self, b: &'v Body<'v>) -> Self::Result {
+    fn visit_body(&mut self, b: &Body<'v>) -> Self::Result {
         walk_body(self, b)
     }
 
@@ -578,7 +578,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) -> V::
     V::Result::output()
 }
 
-pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) -> V::Result {
+pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &Body<'v>) -> V::Result {
     walk_list!(visitor, visit_param, body.params);
     visitor.visit_expr(body.value)
 }