…e_userspace_types_send, r=Nilstrieb,dtolnay

Making `User<T>` and `User<[T]>` `Send`

All `User` types in SGX point to owned memory in userspace. Special care is always needed when accessing this memory as it must be assumed that an attacker is always able to change its content. Therefore, we can also easily transfer this memory between thread boundaries.

cc: `@mzohreva` `@vn971` `@belalH` `@jethrogb`

…llaumeGomez

Rollup of 7 pull requests

Successful merges:

 - rust-lang#117372 (Update stdarch submodule)
 - rust-lang#118241 (Making `User<T>` and `User<[T]>` `Send`)
 - rust-lang#118748 (std: getrandom simplification for freebsd.)
 - rust-lang#119527 (don't reexport atomic::ordering via rustc_data_structures, use std import)
 - rust-lang#119699 (Merge dead bb pruning and unreachable bb deduplication.)
 - rust-lang#119723 (Remove `-Zdont-buffer-diagnostics`.)
 - rust-lang#119756 (rustdoc-search: reuse individual types in function signatures)

r? `@ghost`
`@rustbot` modify labels: rollup

…llaumeGomez

Rollup of 5 pull requests

Successful merges:

 - rust-lang#118241 (Making `User<T>` and `User<[T]>` `Send`)
 - rust-lang#118645 (chore: Bump compiler_builtins)
 - rust-lang#118680 (Add support for shell argfiles)
 - rust-lang#119721 (`~const` trait and projection bounds do not imply their non-const counterparts)
 - rust-lang#119768 (core: panic: fix broken link)

r? `@ghost`
`@rustbot` modify labels: rollup