Rollup merge of #69372 - yawpitch:master, r=varkor

Updates links in various Compiler Error Index entries

Currently many of the links in the online https://doc.rust-lang.org/error-index.html are not clickable, and many of them don't resolve correctly as they point to older versions of rustbyexample and the reference.

Author: pietroalbini

src/librustc_error_codes/error_codes/E0080.md

@@ -14,7 +14,10 @@ constant expression that had to be evaluated. Attempting to divide by 0
 or causing an integer overflow are two ways to induce this error.
 
 Ensure that the expressions given can be evaluated as the desired integer type.
-See the FFI section of the Reference for more information about using a custom
-integer type:
 
-https://doc.rust-lang.org/reference.html#ffi-attributes
+See the [Custom Discriminants][custom-discriminants] section of the Reference
+for more information about setting custom integer types on fieldless enums
+using the [`repr` attribute][repr-attribute].
+
+[custom-discriminants]: https://doc.rust-lang.org/reference/items/enumerations.html#custom-discriminant-values-for-field-less-enumerations
+[repr-attribute]: https://doc.rust-lang.org/reference/type-layout.html#reprc-enums

src/librustc_error_codes/error_codes/E0133.md

@@ -28,4 +28,6 @@ fn main() {
 }
 ```
 
-See also https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html
+See the [unsafe section][unsafe-section] of the Book for more details.
+
+[unsafe-section]: https://doc.rust-lang.org/book/ch19-01-unsafe-rust.html

src/librustc_error_codes/error_codes/E0154.md

@@ -27,7 +27,8 @@ fn f() {
 }
 ```
 
-See the Declaration Statements section of the reference for more information
-about what constitutes an Item declaration and what does not:
+See the [Declaration Statements][declaration-statements] section of the
+reference for more information about what constitutes an item declaration
+and what does not.
 
-https://doc.rust-lang.org/reference.html#statements
+[declaration-statements]: https://doc.rust-lang.org/reference/statements.html#declaration-statements

src/librustc_error_codes/error_codes/E0260.md

@@ -28,7 +28,8 @@ extern crate core as xyz;
 struct abc;
 ```
 
-See the Declaration Statements section of the reference for more information
-about what constitutes an Item declaration and what does not:
+See the [Declaration Statements][declaration-statements] section of the
+reference for more information about what constitutes an item declaration
+and what does not.
 
-https://doc.rust-lang.org/reference.html#statements
+[declaration-statements]: https://doc.rust-lang.org/reference/statements.html#declaration-statements

src/librustc_error_codes/error_codes/E0303.md

@@ -33,4 +33,6 @@ match Some("hi".to_string()) {
 
 The `op_string_ref` binding has type `&Option<&String>` in both cases.
 
-See also https://github.com/rust-lang/rust/issues/14587
+See also [Issue 14587][issue-14587].
+
+[issue-14587]: https://github.com/rust-lang/rust/issues/14587

src/librustc_error_codes/error_codes/E0364.md

@@ -26,7 +26,7 @@ pub use foo::X;
 fn main() {}
 ```
 
-See the 'Use Declarations' section of the reference for more information on
-this topic:
+See the [Use Declarations][use-declarations] section of the reference for
+more information on this topic.
 
-https://doc.rust-lang.org/reference.html#use-declarations
+[use-declarations]: https://doc.rust-lang.org/reference/items/use-declarations.html

src/librustc_error_codes/error_codes/E0365.md

@@ -26,7 +26,7 @@ pub use foo as foo2;
 fn main() {}
 ```
 
-See the 'Use Declarations' section of the reference for more information
-on this topic:
+See the [Use Declarations][use-declarations] section of the reference for
+more information on this topic.
 
-https://doc.rust-lang.org/reference.html#use-declarations
+[use-declarations]: https://doc.rust-lang.org/reference/items/use-declarations.html

src/librustc_error_codes/error_codes/E0382.md

@@ -104,7 +104,7 @@ With this approach, x and y share ownership of the data via the `Rc` (reference
 count type). `RefCell` essentially performs runtime borrow checking: ensuring
 that at most one writer or multiple readers can access the data at any one time.
 
-If you wish to learn more about ownership in Rust, start with the chapter in the
-Book:
+If you wish to learn more about ownership in Rust, start with the
+[Understanding Ownership][understanding-ownership] chapter in the Book.
 
-https://doc.rust-lang.org/book/ch04-00-understanding-ownership.html
+[understanding-ownership]: https://doc.rust-lang.org/book/ch04-00-understanding-ownership.html

src/librustc_error_codes/error_codes/E0387.md

@@ -52,6 +52,6 @@ fn mutable() {
 }
 ```
 
-You can read more about cell types in the API documentation:
+You can read more in the API documentation for [Cell][std-cell].
 
-https://doc.rust-lang.org/std/cell/
+[std-cell]: https://doc.rust-lang.org/std/cell/

src/librustc_error_codes/error_codes/E0455.md

@@ -15,5 +15,7 @@ To solve this error you can use conditional compilation:
 extern {}
 ```
 
-See more:
-https://doc.rust-lang.org/reference/attributes.html#conditional-compilation
+Learn more in the [Conditional Compilation][conditional-compilation] section
+of the Reference.
+
+[conditional-compilation]: https://doc.rust-lang.org/reference/attributes.html#conditional-compilation