Auto merge of #8880 - hellow554:rustfix_update, r=Manishearth

Add some testcases for recent rustfix update

changelog: none

This adds a testcase for a bugfix that has been fixed by https://github.com/rust-lang/rustfix/tree/v0.6.1

`rustfix` is pulled in by `compiletest_rs`. So to test that the correct rustfix version is used, I added one (and a half) testcase.

I tried to add a testcase for #8734 as well, but interesting enough the rustfix is wrong:

```diff
 fn issue8734() {
     let _ = [0u8, 1, 2, 3]
         .into_iter()
-        .and_then(|n| match n {
+        .flat_map(|n| match n {
+            1 => [n
+                .saturating_add(1)
             1 => [n
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)
                 .saturating_add(1)],
             n => [n],
         });
 }
```

this needs some investigation and then this testcase needs to be enabled by commenting it out

closes #8878
related to #8734

0 files changed, 0 insertions, 0 deletions