hack to avoid incorrect suggestion

Author: estebank

src/librustc/traits/error_reporting.rs

@@ -1055,6 +1055,13 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                 .filter(|c| !c.is_whitespace())
                 .take_while(|c| *c == '&')
                 .count();
+            if let Some('\'') = snippet.chars()
+                .filter(|c| !c.is_whitespace())
+                .skip(refs_number)
+                .next()
+            { // Do not suggest removal of borrow from type arguments.
+                return;
+            }
 
             let mut trait_type = trait_ref.self_ty();
 

src/test/ui/kindck/kindck-copy.stderr

@@ -5,10 +5,7 @@ LL | fn assert_copy<T:Copy>() { }
    |    -----------   ---- required by this bound in `assert_copy`
 ...
 LL |     assert_copy::<&'static mut isize>();
-   |                   -^^^^^^^^^^^^^^^^^
-   |                   |
-   |                   the trait `std::marker::Copy` is not implemented for `&'static mut isize`
-   |                   help: consider removing 1 leading `&`-references
+   |                   ^^^^^^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `&'static mut isize`
    |
    = help: the following implementations were found:
              <isize as std::marker::Copy>
@@ -20,10 +17,7 @@ LL | fn assert_copy<T:Copy>() { }
    |    -----------   ---- required by this bound in `assert_copy`
 ...
 LL |     assert_copy::<&'a mut isize>();
-   |                   -^^^^^^^^^^^^
-   |                   |
-   |                   the trait `std::marker::Copy` is not implemented for `&'a mut isize`
-   |                   help: consider removing 1 leading `&`-references
+   |                   ^^^^^^^^^^^^^ the trait `std::marker::Copy` is not implemented for `&'a mut isize`
    |
    = help: the following implementations were found:
              <isize as std::marker::Copy>