Auto merge of #64510 - Centril:rollup-m03zsq8, r=Centril

Rollup of 10 pull requests

Successful merges:

 - #63955 (Make sure interned constants are immutable)
 - #64028 (Stabilize `Vec::new` and `String::new` as `const fn`s)
 - #64119 (ci: ensure all tool maintainers are assignable on issues)
 - #64444 (fix building libstd without backtrace feature)
 - #64446 (Fix build script sanitizer check.)
 - #64451 (when Miri tests are not passing, do not add Miri component)
 - #64467 (Hide diagnostics emitted during --cfg parsing)
 - #64497 (Don't print the "total" `-Ztime-passes` output if `--prints=...` is also given)
 - #64499 (Use `Symbol` in two more functions.)
 - #64504 (use println!() instead of println!(""))

Failed merges:

r? @ghost

1 files changed, 1 insertions, 1 deletions

diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index b65f191836e..1166e7b5df2 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -369,7 +369,7 @@ impl String {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[rustc_const_unstable(feature = "const_string_new")]
+    #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_string_new"))]
     pub const fn new() -> String {
         String { vec: Vec::new() }
     }