Auto merge of #57568 - Centril:rollup, r=Centril

Rollup of 16 pull requests

Successful merges:

 - #57351 (Don't actually create a full MIR stack frame when not needed)
 - #57353 (Optimise floating point `is_finite` (2x) and `is_infinite` (1.6x).)
 - #57412 (Improve the wording)
 - #57436 (save-analysis: use a fallback when access levels couldn't be computed)
 - #57453 (lldb_batchmode.py: try `import _thread` for Python 3)
 - #57454 (Some cleanups for core::fmt)
 - #57461 (Change `String` to `&'static str` in `ParseResult::Failure`.)
 - #57473 (std: Render large exit codes as hex on Windows)
 - #57474 (save-analysis: Get path def from parent in case there's no def for the path itself.)
 - #57494 (Speed up item_bodies for large match statements involving regions)
 - #57496 (re-do docs for core::cmp)
 - #57508 (rustdoc: Allow inlining of reexported crates and crate items)
 - #57547 (Use `ptr::eq` where applicable)
 - #57557 (resolve: Mark extern crate items as used in more cases)
 - #57560 (hygiene: Do not treat `Self` ctor as a local variable)
 - #57564 (Update the const fn tracking issue to the new metabug)

Failed merges:

r? @ghost

3 files changed, 5 insertions, 5 deletions

diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index d55f785bd9b..b4003ac729a 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -271,7 +271,7 @@ pub enum ParseResult<T> {
     Success(T),
     /// Arm failed to match. If the second parameter is `token::Eof`, it indicates an unexpected
     /// end of macro invocation. Otherwise, it indicates that no rules expected the given token.
-    Failure(syntax_pos::Span, Token, String),
+    Failure(syntax_pos::Span, Token, &'static str),
     /// Fatal error (malformed macro?). Abort compilation.
     Error(syntax_pos::Span, String),
 }
@@ -721,7 +721,7 @@ pub fn parse(
                         sess.source_map().next_point(parser.span)
                     },
                     token::Eof,
-                    "missing tokens in macro arguments".to_string(),
+                    "missing tokens in macro arguments",
                 );
             }
         }
@@ -760,7 +760,7 @@ pub fn parse(
             return Failure(
                 parser.span,
                 parser.token,
-                "no rules expected this token in macro call".to_string(),
+                "no rules expected this token in macro call",
             );
         }
         // Dump all possible `next_items` into `cur_items` for the next iteration.
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index cb8fbce6697..24202ca8fbd 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -202,7 +202,7 @@ fn generic_extension<'cx>(cx: &'cx mut ExtCtxt,
     let best_fail_msg = parse_failure_msg(best_fail_tok.expect("ran no matchers"));
     let span = best_fail_spot.substitute_dummy(sp);
     let mut err = cx.struct_span_err(span, &best_fail_msg);
-    err.span_label(span, best_fail_text.unwrap_or(best_fail_msg));
+    err.span_label(span, best_fail_text.unwrap_or(&best_fail_msg));
     if let Some(sp) = def_span {
         if cx.source_map().span_to_filename(sp).is_real() && !sp.is_dummy() {
             err.span_label(cx.source_map().def_span(sp), "when calling this macro");
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 89da1a219b7..9b4231d8803 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -191,7 +191,7 @@ declare_features! (
     (active, slice_patterns, "1.0.0", Some(23121), None),
 
     // Allows the definition of `const` functions with some advanced features.
-    (active, const_fn, "1.2.0", Some(24111), None),
+    (active, const_fn, "1.2.0", Some(57563), None),
 
     // Allows accessing fields of unions inside `const` functions.
     (active, const_fn_union, "1.27.0", Some(51909), None),