Move platform modules into `sys::pal`
This is the initial step of #117276. `sys` just re-exports everything from the current `sys` for now, I'll move the implementations for the individual features one-by-one after this PR merges.
libtest: Fix padding of benchmarks run as tests
### Summary
The first commit adds regression tests for libtest padding.
The second commit fixes padding for benches run as tests and updates the blessed output of the regression tests to make it clear what effect the fix has on padding.
Closes#104092 which is **E-help-wanted** and **regression-from-stable-to-stable**
### More details
Before this fix we applied padding _before_ manually doing what `convert_benchmarks_to_tests()` does which affects padding calculations. Instead use `convert_benchmarks_to_tests()` first if applicable and then apply padding afterwards so it becomes correct.
Benches should only be padded when run as benches to make it easy to compare the benchmark numbers. Not when run as tests.
r? `@ghost` until CI passes.
Add Benchmarks for int_pow Methods.
There is quite a bit of room for improvement in performance of the `int_pow` family of methods. I added benchmarks for those functions. In particular, there are benchmarks for small compile-time bases to measure the effect of #114390. ~~I added a lot (245), but all but 22 of them are marked with `#[ignore]`. There are a lot of macros, and I would appreciate feedback on how to simplify them.~~
~~To run benches relevant to #114390, use `./x bench core --stage 1 -- pow_base_const --include-ignored`.~~
A more efficient slice comparison implementation for T: !BytewiseEq
(This is a follow up PR on #113654)
This PR changes the implementation for `[T]` slice comparison when `T: !BytewiseEq`. The previous implementation using zip was not optimized properly by the compiler, which didn't leverage the fact that both length were equal. Performance improvements are for example 20% when testing that `[Some(0_u64); 4096].as_slice() == [Some(0_u64); 4096].as_slice()`.
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``
Fix broken build for ESP IDF due to #119026
`target_os = "espidf"` in `libc` lacks the `SOMAXCONN` constant, but that's probably irrelevant in this context, as `UnixListener` is not supported on ESP IDF - it being a single process "OS" only.
The PR just re-uses the `128` constant so that the code builds. Trying to use the listener on ESP IDF will fail with `ENOSYS`, which is fine.
*UPDATE* Might not fail with `ENOSYS` - need to test what error code would be returned, but that doesn`t change anything.
Use `assert_unsafe_precondition` for `char::from_u32_unchecked`
Use `assert_unsafe_precondition` in `char::from_u32_unchecked` so that it can be stabilized as `const`.
Rewrite `pin` module documentation to clarify usage and invariants
The documentation of `pin` today does not give a complete treatment of pinning from first principles, nor does it adequately help build intuition and understanding for how the different elements of the pinning story fit together.
This rewrite attempts to address these in a way that makes the concept more approachable while also making the documentation more normative.
This PR picks up where `@mcy` left off in #88500 (thanks to him for the original work and `@Manishearth` for mentioning it such that I originally found it). I've directly incorporated much of the feedback left on the original PR and have rewritten and changed some of the main conceits of the prose to better adhere to the feedback from the reviewers on that PR or just explain something in (hopefully) a better way.
