Use suggestions instead of notes ref mismatches

On type mismatch errors, use a suggestion when encountering minimal
differences in type differences due to refs, instead of a note.

src/test/ui/deref-suggestion.stderr

@@ -17,31 +17,37 @@ error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:23:10
    |
 23 |     foo3(u); //~ ERROR mismatched types
-   |          ^ expected u32, found &u32
+   |          ^
+   |          |
+   |          expected u32, found &u32
+   |          help: consider dereferencing the borrow: `*u`
    |
    = note: expected type `u32`
               found type `&u32`
-   = help: try with `*u`
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:30:9
    |
 30 |     foo(&"aaa".to_owned()); //~ ERROR mismatched types
-   |         ^^^^^^^^^^^^^^^^^ expected struct `std::string::String`, found reference
+   |         ^^^^^^^^^^^^^^^^^
+   |         |
+   |         expected struct `std::string::String`, found reference
+   |         help: consider removing the borrow: `"aaa".to_owned()`
    |
    = note: expected type `std::string::String`
               found type `&std::string::String`
-   = help: try with `"aaa".to_owned()`
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:31:9
    |
 31 |     foo(&mut "aaa".to_owned()); //~ ERROR mismatched types
-   |         ^^^^^^^^^^^^^^^^^^^^^ expected struct `std::string::String`, found mutable reference
+   |         ^^^^^^^^^^^^^^^^^^^^^
+   |         |
+   |         expected struct `std::string::String`, found mutable reference
+   |         help: consider removing the borrow: `"aaa".to_owned()`
    |
    = note: expected type `std::string::String`
               found type `&mut std::string::String`
-   = help: try with `"aaa".to_owned()`
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:12:20

src/test/ui/span/coerce-suggestions.rs

@@ -23,7 +23,7 @@ fn main() {
     //~^ ERROR E0308
     //~| NOTE expected &str, found struct `std::string::String`
     //~| NOTE expected type `&str`
-    //~| HELP try with `&String::new()`
+    //~| HELP consider borrowing here
     let y = String::new();
     test(&y);
     //~^ ERROR E0308

src/test/ui/span/coerce-suggestions.stderr

@@ -14,11 +14,13 @@ error[E0308]: mismatched types
   --> $DIR/coerce-suggestions.rs:22:19
    |
 22 |     let x: &str = String::new();
-   |                   ^^^^^^^^^^^^^ expected &str, found struct `std::string::String`
+   |                   ^^^^^^^^^^^^^
+   |                   |
+   |                   expected &str, found struct `std::string::String`
+   |                   help: consider borrowing here: `&String::new()`
    |
    = note: expected type `&str`
               found type `std::string::String`
-   = help: try with `&String::new()`
 
 error[E0308]: mismatched types
   --> $DIR/coerce-suggestions.rs:28:10
@@ -48,11 +50,13 @@ error[E0308]: mismatched types
   --> $DIR/coerce-suggestions.rs:42:9
    |
 42 |     s = format!("foo");
-   |         ^^^^^^^^^^^^^^ expected mutable reference, found struct `std::string::String`
+   |         ^^^^^^^^^^^^^^
+   |         |
+   |         expected mutable reference, found struct `std::string::String`
+   |         help: consider mutably borrowing here: `&mut format!("foo")`
    |
    = note: expected type `&mut std::string::String`
               found type `std::string::String`
-   = help: try with `&mut format!("foo")`
    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
 
 error: aborting due to 6 previous errors

src/test/ui/str-lit-type-mismatch.stderr

@@ -2,31 +2,37 @@ error[E0308]: mismatched types
   --> $DIR/str-lit-type-mismatch.rs:13:20
    |
 13 |     let x: &[u8] = "foo"; //~ ERROR mismatched types
-   |                    ^^^^^ expected slice, found str
+   |                    ^^^^^
+   |                    |
+   |                    expected slice, found str
+   |                    help: consider adding a leading `b`: `b"foo"`
    |
    = note: expected type `&[u8]`
               found type `&'static str`
-   = help: try `b"foo"`
 
 error[E0308]: mismatched types
   --> $DIR/str-lit-type-mismatch.rs:14:23
    |
 14 |     let y: &[u8; 4] = "baaa"; //~ ERROR mismatched types
-   |                       ^^^^^^ expected array of 4 elements, found str
+   |                       ^^^^^^
+   |                       |
+   |                       expected array of 4 elements, found str
+   |                       help: consider adding a leading `b`: `b"baaa"`
    |
    = note: expected type `&[u8; 4]`
               found type `&'static str`
-   = help: try `b"baaa"`
 
 error[E0308]: mismatched types
   --> $DIR/str-lit-type-mismatch.rs:15:19
    |
 15 |     let z: &str = b"foo"; //~ ERROR mismatched types
-   |                   ^^^^^^ expected str, found array of 3 elements
+   |                   ^^^^^^
+   |                   |
+   |                   expected str, found array of 3 elements
+   |                   help: consider removing the leading `b`: `"foo"`
    |
    = note: expected type `&str`
               found type `&'static [u8; 3]`
-   = help: try `"foo"`
 
 error: aborting due to 3 previous errors
 

src/test/ui/suggestions/str-array-assignment.rs

@@ -28,5 +28,5 @@ fn main() { //~ NOTE expected `()` because of default return type
   //~^ ERROR mismatched types
   //~| NOTE expected &str, found str
   //~| NOTE expected type
-  //~| HELP try with `&s[..2]`
+  //~| HELP consider borrowing here
 }

src/test/ui/suggestions/str-array-assignment.stderr

@@ -34,11 +34,13 @@ error[E0308]: mismatched types
   --> $DIR/str-array-assignment.rs:27:17
    |
 27 |   let w: &str = s[..2];
-   |                 ^^^^^^ expected &str, found str
+   |                 ^^^^^^
+   |                 |
+   |                 expected &str, found str
+   |                 help: consider borrowing here: `&s[..2]`
    |
    = note: expected type `&str`
               found type `str`
-   = help: try with `&s[..2]`
 
 error: aborting due to 4 previous errors