Rollup merge of #106863 - anden3:compiler-double-spaces, r=Nilstrieb

Remove various double spaces in compiler source comments.

Was asked to do it by `@Nilstrieb`

compiler/rustc_parse/src/parser/pat.rs

@@ -469,7 +469,7 @@ impl<'a> Parser<'a> {
     /// Try to recover the more general form `intersect ::= $pat_lhs @ $pat_rhs`.
     ///
     /// Allowed binding patterns generated by `binding ::= ref? mut? $ident @ $pat_rhs`
-    /// should already have been parsed by now  at this point,
+    /// should already have been parsed by now at this point,
     /// if the next token is `@` then we can try to parse the more general form.
     ///
     /// Consult `parse_pat_ident` for the `binding` grammar.