Remove explicit -Zborrowck=mir which does not affect test anymore

Author: oli-obk

src/test/ui/impl-trait/multiple-lifetimes/error-handling-2.rs

@@ -1,5 +1,3 @@
-// compile-flags:-Zborrowck=mir
-
 #![feature(type_alias_impl_trait)]
 
 #[derive(Clone)]

src/test/ui/impl-trait/multiple-lifetimes/error-handling-2.stderr

@@ -1,5 +1,5 @@
 error[E0700]: hidden type for `impl Trait` captures lifetime that does not appear in bounds
-  --> $DIR/error-handling-2.rs:12:60
+  --> $DIR/error-handling-2.rs:10:60
    |
 LL | fn foo<'a: 'b, 'b, 'c>(x: &'static i32, mut y: &'a i32) -> E<'b, 'c> {
    |        --                                                  ^^^^^^^^^

src/test/ui/impl-trait/multiple-lifetimes/error-handling.rs

@@ -1,5 +1,3 @@
-// compile-flags:-Zborrowck=mir
-
 #![feature(type_alias_impl_trait)]
 
 #[derive(Clone)]

src/test/ui/impl-trait/multiple-lifetimes/error-handling.stderr

@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/error-handling.rs:22:16
+  --> $DIR/error-handling.rs:20:16
    |
 LL | fn foo<'a, 'b, 'c>(x: &'static i32, mut y: &'a i32) -> E<'b, 'c> {
    |        --  -- lifetime `'b` defined here