remove unnecessary compile-flags comments

src/test/ui/nll/borrowed-referent-issue-38899.rs

@@ -10,8 +10,6 @@
 
 // Regression test for issue #38899
 
-// compile-flags:-Znll -Zborrowck=mir -Zverbose
-
 #![feature(nll)]
 #![allow(dead_code)]
 

src/test/ui/nll/borrowed-referent-issue-38899.stderr

@@ -1,10 +1,10 @@
 error[E0502]: cannot borrow `*block.current` as immutable because it is also borrowed as mutable
-  --> $DIR/borrowed-referent-issue-38899.rs:26:21
+  --> $DIR/borrowed-referent-issue-38899.rs:24:21
    |
-24 |     let x = &mut block;
+22 |     let x = &mut block;
    |             ---------- mutable borrow occurs here
-25 |     println!("{}", x.current);
-26 |     let p: &'a u8 = &*block.current;
+23 |     println!("{}", x.current);
+24 |     let p: &'a u8 = &*block.current;
    |                     ^^^^^^^^^^^^^^^ immutable borrow occurs here
 
 error: aborting due to previous error

src/test/ui/nll/return-ref-mut-issue-46557.rs

@@ -10,8 +10,6 @@
 
 // Regression test for issue #46557
 
-// compile-flags:-Znll -Zborrowck=mir -Zverbose
-
 #![feature(nll)]
 #![allow(dead_code)]
 

src/test/ui/nll/return-ref-mut-issue-46557.stderr

@@ -1,10 +1,10 @@
 error[E0597]: borrowed value does not live long enough
-  --> $DIR/return-ref-mut-issue-46557.rs:19:21
+  --> $DIR/return-ref-mut-issue-46557.rs:17:21
    |
-19 |     let ref mut x = 1234543; //~ ERROR borrowed value does not live long enough [E0597]
+17 |     let ref mut x = 1234543; //~ ERROR borrowed value does not live long enough [E0597]
    |                     ^^^^^^^ temporary value does not live long enough
-20 |     x
-21 | }
+18 |     x
+19 | }
    |  - temporary value only lives until here
    |
    = note: borrowed value must be valid for lifetime '_#2r...