Rollup merge of #109075 - joboet:lazylock_backtrace, r=workingjubilee

Use `LazyLock` to lazily resolve backtraces

By using TAIT to name the initializing closure, `LazyLock` can be used to replace the current `LazilyResolvedCapture`.

library/std/src/lib.rs

@@ -272,6 +272,7 @@
 #![feature(staged_api)]
 #![feature(thread_local)]
 #![feature(try_blocks)]
+#![feature(type_alias_impl_trait)]
 #![feature(utf8_chunks)]
 // tidy-alphabetical-end
 //