Auto merge of #129063 - the8472:cold-opt-size, r=Amanieu

Apply size optimizations to panic machinery and some cold functions

* std dependencies gimli and addr2line are now built with opt-level=s
* various panic-related methods and `#[cold]` methods are now marked `#[optimize(size)]`

Panics should be cold enough that it doesn't make sense to optimize them for speed. The only tradeoff here is if someone does a lot of backtrace captures (without panics) and printing then the opt-level change might impact their perf.

Seems to be the first use of the optimize attribute. Tracking issue #54882

library/core/src/lib.rs

@@ -234,6 +234,7 @@
 #![feature(never_type)]
 #![feature(no_core)]
 #![feature(no_sanitize)]
+#![feature(optimize_attribute)]
 #![feature(prelude_import)]
 #![feature(repr_simd)]
 #![feature(rustc_allow_const_fn_unstable)]