Rollup merge of #34378 - liigo:patch-10, r=Manishearth

diagnostics comes from different places now

Author: Manishearth

src/doc/rustc-ux-guidelines.md

@@ -56,7 +56,19 @@ Error explanations are long form descriptions of error messages provided with
 the compiler. They are accessible via the `--explain` flag. Each explanation
 comes with an example of how to trigger it and advice on how to fix it.
 
-* All of them are accessible [online](https://github.com/rust-lang/rust/blob/master/src/librustc/diagnostics.rs).
+* All of them are accessible [online](http://doc.rust-lang.org/error-index.html),
+  which are auto-generated from rustc source code in different places:
+  [librustc](https://github.com/rust-lang/rust/blob/master/src/librustc/diagnostics.rs),
+  [librustc_borrowck](https://github.com/rust-lang/rust/blob/master/src/librustc_borrowck/diagnostics.rs),
+  [librustc_const_eval](https://github.com/rust-lang/rust/blob/master/src/librustc_const_eval/diagnostics.rs),
+  [librustc_lint](https://github.com/rust-lang/rust/blob/master/src/librustc_lint/types.rs),
+  [librustc_metadata](https://github.com/rust-lang/rust/blob/master/src/librustc_metadata/diagnostics.rs),
+  [librustc_mir](https://github.com/rust-lang/rust/blob/master/src/librustc_mir/diagnostics.rs),
+  [librustc_passes](https://github.com/rust-lang/rust/blob/master/src/librustc_passes/diagnostics.rs),
+  [librustc_privacy](https://github.com/rust-lang/rust/blob/master/src/librustc_privacy/diagnostics.rs),
+  [librustc_resolve](https://github.com/rust-lang/rust/blob/master/src/librustc_resolve/diagnostics.rs),
+  [librustc_trans](https://github.com/rust-lang/rust/blob/master/src/librustc_trans/diagnostics.rs),
+  [librustc_typeck](https://github.com/rust-lang/rust/blob/master/src/librustc_typeck/diagnostics.rs).
 * Explanations have full markdown support. Use it, especially to highlight
 code with backticks.
 * When talking about the compiler, call it `the compiler`, not `Rust` or