Auto merge of #117928 - nnethercote:rustc_ast_pretty, r=fee1-dead

`rustc_ast_pretty` cleanups

Some improvements I found while looking at this code.

r? `@fee1-dead`

compiler/rustc_interface/src/passes.rs

@@ -114,7 +114,7 @@ impl LintStoreExpand for LintStoreExpandImpl<'_> {
     }
 }
 
-/// Runs the "early phases" of the compiler: initial `cfg` processing, loading compiler plugins,
+/// Runs the "early phases" of the compiler: initial `cfg` processing,
 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 /// harness if one is to be provided, injection of a dependency on the
 /// standard library and prelude, and name resolution.