Use https URLs to refer to rust-lang.org where appropriate.

Also fixes a few outdated links.

src/test/compile-fail/loops-reject-duplicate-labels-2.rs

@@ -16,7 +16,7 @@
 //
 // This is testing the generalization (to the whole function body)
 // discussed here:
-// http://internals.rust-lang.org/t/psa-rejecting-duplicate-loop-labels/1833
+// https://internals.rust-lang.org/t/psa-rejecting-duplicate-loop-labels/1833
 
 pub fn foo() {
     { 'fl: for _ in 0..10 { break; } }   //~ NOTE shadowed label `'fl` declared here

src/test/run-pass/cleanup-arm-conditional.rs

@@ -8,16 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// copyright 2014 the rust project developers. see the copyright
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/copyright.
-//
-// licensed under the apache license, version 2.0 <license-apache or
-// http://www.apache.org/licenses/license-2.0> or the mit license
-// <license-mit or http://opensource.org/licenses/mit>, at your
-// option. this file may not be copied, modified, or distributed
-// except according to those terms.
-
 // Test that cleanup scope for temporaries created in a match
 // arm is confined to the match arm itself.
 

src/test/run-pass/cleanup-shortcircuit.rs

@@ -8,16 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// copyright 2014 the rust project developers. see the copyright
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/copyright.
-//
-// licensed under the apache license, version 2.0 <license-apache or
-// http://www.apache.org/licenses/license-2.0> or the mit license
-// <license-mit or http://opensource.org/licenses/mit>, at your
-// option. this file may not be copied, modified, or distributed
-// except according to those terms.
-
 // Test that cleanups for the RHS of shortcircuiting operators work.
 
 // pretty-expanded FIXME #23616