Revert #119515 single line where clause style guide

src/doc/style-guide/src/editions.md

@@ -46,7 +46,6 @@ include:
 - Miscellaneous `rustfmt` bugfixes.
 - Use version-sort (sort `x8`, `x16`, `x32`, `x64`, `x128` in that order).
 - Change "ASCIIbetical" sort to Unicode-aware "non-lowercase before lowercase".
-- Format single associated type `where` clauses on the same line if they fit.
 
 ## Rust 2015/2018/2021 style edition
 

src/doc/style-guide/src/items.md

@@ -295,18 +295,8 @@ Prefer to use single-letter names for generic parameters.
 
 These rules apply for `where` clauses on any item.
 
-If a where clause is short, and appears on a short one-line function
-declaration with no body or on a short type with no `=`, format it on
-the same line as the declaration:
-
-```rust
-fn new(&self) -> Self where Self: Sized;
-
-type Item<'a>: SomeTrait where Self: 'a;
-```
-
-Otherwise, if immediately following a closing bracket of any kind, write the
-keyword `where` on the same line, with a space before it.
+If immediately following a closing bracket of any kind, write the keyword
+`where` on the same line, with a space before it.
 
 Otherwise, put `where` on a new line at the same indentation level. Put each
 component of a `where` clause on its own line, block-indented. Use a trailing
@@ -357,7 +347,7 @@ where
 ```
 
 If a `where` clause is very short, prefer using an inline bound on the type
-parameter if possible.
+parameter.
 
 If a component of a `where` clause does not fit and contains `+`, break it
 before each `+` and block-indent the continuation lines. Put each bound on its
@@ -431,21 +421,9 @@ Format associated types like type aliases. Where an associated type has a
 bound, put a space after the colon but not before:
 
 ```rust
-type Foo: Bar;
+pub type Foo: Bar;
 ```
 
-If an associated type is short, has no `=`, and has a `where` clause with only
-one entry, format the entire type declaration including the `where` clause on
-the same line if it fits:
-
-```rust
-type Item<'a> where Self: 'a;
-type Item<'a>: PartialEq + Send where Self: 'a;
-```
-
-If the associated type has a `=`, or if the `where` clause contains multiple
-entries, format it across multiple lines as with a type alias.
-
 ## extern items
 
 When writing extern items (such as `extern "C" fn`), always specify the ABI.