with the change to llvm 10 the parameter
LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN do not do any thing as
min and soft error is the same.
see https://github.com/rust-lang/llvm-project/blob/86b120e6f302d39cd6973b6391fb299d7bc22122/llvm/cmake/modules/CheckCompilerVersion.cmake

- Update the list of supported architectures.
- Clarify issues with LLVM's use of reserved registers.

…c` item's initializer

…ith --stage 0

… without text after SAFETY:)

there are three significantly different things printed below

older toolchains not valid anymore

with the change to llvm 10 the parameter
LLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN do not do anything as min and soft error is the same.
see https://github.com/rust-lang/llvm-project/blob/86b120e6f302d39cd6973b6391fb299d7bc22122/llvm/cmake/modules/CheckCompilerVersion.cmake

Fix regionck failure when converting Index to IndexMut

Fixes rust-lang#74933

Consider an overloaded index expression `base[index]`. Without knowing whether it will be mutated, this will initially be desugared into `<U as Index<T>>::index(&base, index)` for some `U` and `T`. Let `V` be the `expr_ty_adjusted` of `index`.

If this expression ends up being used in any mutable context (or used in a function call with `&mut self` receiver before rust-lang#72280), we will need to fix it up. The current code will rewrite it to `<U as IndexMut<V>>::index_mut(&mut base, index)`. In most cases this is fine as `V` will be equal to `T`, however this is not always true when `V/T` are references, as they may have different region.

This issue is quite subtle before rust-lang#72280 as this code path is only used to fixup function receivers, but after rust-lang#72280 we've made this a common path.

The solution is basically just rewrite it to `<U as IndexMut<T>>::index_mut(&mut base, index)`. `T` can retrieved in the fixup path using `node_substs`.

…tsakis

Update asm! documentation in unstable book

- Update the list of supported architectures.
- Clarify issues with LLVM's use of reserved registers.

…elude, r=jyn514

Move to doc links inside the prelude

Helps with rust-lang#75080.

@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc

…me, r=jyn514

Move to doc links inside std/time.rs

Helps with rust-lang#75080.

@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc

Add a function to `TyCtxt` for computing an `Allocation` for a `static` item's initializer

r? @RalfJung

miri-side: rust-lang/miri#1507

split out of rust-lang#74949 (comment) to make that PR leaner

Switch to intra-doc links in library/std/src/os/*/fs.rs

Partial fix for rust-lang#75080

@rustbot modify labels: T-doc, T-rustdoc, A-intra-doc-links

…y-comments, r=Mark-Simulacrum

Accept more safety comments

This accepts more `// SAFETY:` comments from `tidy`.

This is done after the current behaviour of requiring text one the same line (because spaces are stripped so the last space never pass if there is no text on the same line) bit me once more in rust-lang#75066

This could potentially accept empty `// SAFETY:` comments but `tidy` is an internal tool used only here so my reasoning is reviews will catch those.

fix wrong word in documentation

Change "two" to "three", since there are three significantly different things printed below that sentence:

---

While these:
```rust
println!("{}, `{name:.*}` has 3 fractional digits", "Hello", 3, name=1234.56);
println!("{}, `{name:.*}` has 3 characters", "Hello", 3, name="1234.56");
println!("{}, `{name:>8.*}` has 3 right-aligned characters", "Hello", 3, name="1234.56");
```

print two significantly different things:

``` rust
Hello, `1234.560` has 3 fractional digits
Hello, `123` has 3 characters
Hello, `     123` has 3 right-aligned characters
```
---
[`https://doc.rust-lang.org/std/fmt/#precision`](https://doc.rust-lang.org/std/fmt/#precision)