Remove redundant link texts
Most of these links are followed by a parenthesized expression. I think that the redundant link texts were added to prevent interpretation as an inline link. This is unnecessary since the closing square bracket and opening parenthesis are separated by whitespace.
Use NonNull in slice::Iter and slice::IterMut.
`ptr` of `slice::Iter` and `slice::IterMut` can never be null, but this
fact wasn't exploited for layout optimizations. By changing `ptr` from
`*<mutability> T` to `NonNull<T>`, the compiler can now optimize layout
of `Option<Iter<'a, T>>`.
Closes#67228
Implement padding for IpAddr without heap alloc
Implements padding for `IpAddr`s without heap allocations.
This fixes issue #66810 .
cc @jethrogb @mzohreva
Add LLVM `skip-rebuild` option to `x.py`
This PR reimplements parts of @Walther's work from #65848, and closes#65612.
I decided not to implement the [arguments to override this setting](https://github.com/rust-lang/rust/issues/65612#issuecomment-544247546) in this PR. If there's strong feeling that this change shouldn't be merged without the overrides then I'm happy to close this until I've had a chance to add them in. Otherwise I'll aim to submit a second PR with those this weekend.
I'd have liked to have tested the change in `native.rs`, but there didn't seem to be any existing test infrastructure. I ran this a few times manually and it _worked on my machine_ though... 😬
Various const eval and pattern matching ICE fixes
r? @RalfJung
cc @spastorino
This PR does not change existing behaviour anymore and just fixes a bunch of ICEs reachable from user code (sometimes even on stable via obscure union transmutes).
`ptr` of `slice::Iter` and `slice::IterMut` can never be null, but this
fact wasn't exploited for layout optimizations. By changing `ptr` from
`*<mutability> T` to `NonNull<T>`, the compiler can now optimize layout
of `Option<Iter<'a, T>>`.
Prepare for lowering or-patterns
This is probably best reviewed commit-by-commit.
* Rustfmt `rustc_mir::build::{self, matches}`
* Remove `-Znll-dont-emit-read-for-match`
* Split `match_expr` into smaller functions
* Feature gate or-patterns in const contexts
cc https://github.com/rust-lang/rust/issues/54883
r? @Centril
