Auto merge of #102450 - JohnTitor:rollup-ahleg93, r=JohnTitor

Rollup of 8 pull requests

Successful merges:

 - #98368 (Make `std::os::fd` public.)
 - #102085 (Code refactoring smart_resolve_report_errors)
 - #102351 (Improve E0585 help)
 - #102368 (Add a niche to `Duration`, unix `SystemTime`, and non-apple `Instant`)
 - #102393 (Add regression test for issue 94923)
 - #102399 (Account for use of index-based lifetime names in print of binder)
 - #102416 (remove FIXME, improve documentation)
 - #102433 (env::temp_dir: fix a typo)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_error_messages/locales/en-US/parser.ftl

@@ -245,7 +245,7 @@ parser_assignment_else_not_allowed = <assignment> ... else {"{"} ... {"}"} is no
 parser_expected_statement_after_outer_attr = expected statement after outer attribute
 
 parser_doc_comment_does_not_document_anything = found a documentation comment that doesn't document anything
-    .help = doc comments must come before what they document, maybe a comment was intended with `//`?
+    .help = doc comments must come before what they document, if a comment was intended use `//`
     .suggestion = missing comma here
 
 parser_const_let_mutually_exclusive = `const` and `let` are mutually exclusive

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -2173,10 +2173,16 @@ impl<'tcx> FmtPrinter<'_, 'tcx> {
 
         let mut region_index = self.region_index;
         let mut next_name = |this: &Self| {
-            let name = name_by_region_index(region_index, &mut available_names, num_available);
-            debug!(?name);
-            region_index += 1;
-            assert!(!this.used_region_names.contains(&name));
+            let mut name;
+
+            loop {
+                name = name_by_region_index(region_index, &mut available_names, num_available);
+                region_index += 1;
+
+                if !this.used_region_names.contains(&name) {
+                    break;
+                }
+            }
 
             name
         };

compiler/rustc_parse/src/parser/item.rs

@@ -760,8 +760,8 @@ impl<'a> Parser<'a> {
                 )
                 .span_label(self.token.span, "this doc comment doesn't document anything")
                 .help(
-                    "doc comments must come before what they document, maybe a \
-                    comment was intended with `//`?",
+                    "doc comments must come before what they document, if a comment was \
+                    intended use `//`",
                 )
                 .emit();
                 self.bump();