Auto merge of #68975 - Dylan-DPC:rollup-jzab8oh, r=Dylan-DPC

Rollup of 7 pull requests

Successful merges:

 - #68718 (Move `rustc_hir::def_id` to `rustc_span::def_id`)
 - #68834 (Fix and test implementation of BTreeMap's first/last_entry, pop_first/last)
 - #68857 (perf: Reduce Vec allocations in normalization by passing &mut Vec)
 - #68918 (Don't use the word "unwrap" to describe "unwrap" methods)
 - #68946 (Mark several functions and methods in core::cmp as #[must_use])
 - #68958 (Clean up E0277 and E0282 explanations)
 - #68960 (codegen: misc cleanups around debuginfo scopes and locations.)

Failed merges:

r? @ghost

2 files changed, 14 insertions, 8 deletions

diff --git a/src/librustc_error_codes/error_codes/E0277.md b/src/librustc_error_codes/error_codes/E0277.md
index 2034a5b988c..2e2cd5e01fb 100644
--- a/src/librustc_error_codes/error_codes/E0277.md
+++ b/src/librustc_error_codes/error_codes/E0277.md
@@ -1,5 +1,7 @@
 You tried to use a type which doesn't implement some trait in a place which
-expected that trait. Erroneous code example:
+expected that trait.
+
+Erroneous code example:
 
 ```compile_fail,E0277
 // here we declare the Foo trait with a bar method
diff --git a/src/librustc_error_codes/error_codes/E0282.md b/src/librustc_error_codes/error_codes/E0282.md
index 54a9de0025a..49d2205f92c 100644
--- a/src/librustc_error_codes/error_codes/E0282.md
+++ b/src/librustc_error_codes/error_codes/E0282.md
@@ -1,3 +1,11 @@
+The compiler could not infer a type and asked for a type annotation.
+
+Erroneous code example:
+
+```compile_fail,E0282
+let x = "hello".chars().rev().collect();
+```
+
 This error indicates that type inference did not result in one unique possible
 type, and extra information is required. In most cases this can be provided
 by adding a type annotation. Sometimes you need to specify a generic type
@@ -8,13 +16,9 @@ parameter with a `FromIterator` bound, which for a `char` iterator is
 implemented by `Vec` and `String` among others. Consider the following snippet
 that reverses the characters of a string:
 
-```compile_fail,E0282
-let x = "hello".chars().rev().collect();
-```
-
-In this case, the compiler cannot infer what the type of `x` should be:
-`Vec<char>` and `String` are both suitable candidates. To specify which type to
-use, you can use a type annotation on `x`:
+In the first code example, the compiler cannot infer what the type of `x` should
+be: `Vec<char>` and `String` are both suitable candidates. To specify which type
+to use, you can use a type annotation on `x`:
 
 ```
 let x: Vec<char> = "hello".chars().rev().collect();