Auto merge of #50290 - kennytm:rollup, r=kennytm

Auto merge of #50290 - kennytm:rollup, r=kennytm

Rollup of 9 pull requests

Successful merges:

 - #49858 (std: Mark `ptr::Unique` with `#[doc(hidden)]`)
 - #49968 (Stabilize dyn trait)
 - #50192 (Add some utilities to `libsyntax`)
 - #50251 (rustc: Disable threads in LLD for wasm)
 - #50263 (rustc: Emit `uwtable` for allocator shims)
 - #50269 (Update `parking_lot` dependencies)
 - #50273 (Allow #[inline] on closures)
 - #50284 (fix search load page failure)
 - #50257 (Don't ICE on tuple struct ctor with incorrect arg count)

Failed merges: