Update ui test suite to nightly-2021-08-12

Author: dtolnay

tests/ui/array_len_suffix.stderr

@@ -7,4 +7,4 @@ error[E0308]: mismatched types
 help: change the type of the numeric literal from `u16` to `usize`
   |
 4 |         fn array() -> [String; 12usize];
-  |                                ^^^^^^^
+  |                                ~~~~~~~

tests/ui/expected_named.stderr

@@ -8,4 +8,4 @@ error[E0106]: missing lifetime specifier
 help: consider using the `'static` lifetime
   |
 5 |         fn borrowed() -> UniquePtr<Borrowed<'static>>;
-  |                                    ^^^^^^^^^^^^^^^^^
+  |                                    ~~~~~~~~~~~~~~~~~

tests/ui/result_no_display.stderr

@@ -1,8 +1,9 @@
 error[E0277]: `NonError` doesn't implement `std::fmt::Display`
- --> $DIR/result_no_display.rs:4:19
+ --> $DIR/result_no_display.rs:1:1
   |
-4 |         fn f() -> Result<()>;
-  |                   ^^^^^^^^^^ `NonError` cannot be formatted with the default formatter
+1 | #[cxx::bridge]
+  | ^^^^^^^^^^^^^^ `NonError` cannot be formatted with the default formatter
   |
   = help: the trait `std::fmt::Display` is not implemented for `NonError`
   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead
+  = note: this error originates in the attribute macro `cxx::bridge` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/unsupported_elided.stderr

@@ -16,4 +16,4 @@ error[E0106]: missing lifetime specifier
 help: consider introducing a named lifetime parameter
   |
 8 |         fn f<'a>(t: &'a T) -> &'a str;
-  |             ^^^^    ^^^^^     ^^^
+  |             ++++    ~~~~~     ~~~