…th 1 when reaching end

These have been bugging me for a while.

- `literal_text`: `src` is also used and is shorter and better.
- `first_char`: used even when "first" doesn't make sense; `c` is
  shorter and better.
- `curr`: `c` is shorter and better.
- `unescaped_char`: `result` is also used and is shorter and better.
- `second_char`: these have a single use and can be elided.

There is some subtlety here.

It's passed to numerous places where we just need an `is_byte` bool.
Passing the bool avoids the need for some assertions.

Also rename `is_bytes()` as `is_byte()`, to better match `Mode::Byte`,
`Mode::ByteStr`, and `Mode::RawByteStr`.

There are three kinds of "byte" literals: byte literals, byte string
literals, and raw byte string literals. None are allowed to have
non-ASCII chars in them.

Two `EscapeError` variants exist for when that constraint is violated.
- `NonAsciiCharInByte`: used for byte literals and byte string literals.
- `NonAsciiCharInByteString`: used for raw byte string literals.

As a result, the messages for raw byte string literals use different
wording, without good reason. Also, byte string literals are incorrectly
described as "byte constants" in some error messages.

This commit eliminates `NonAsciiCharInByteString` so the three cases are
handled similarly, and described correctly. The `mode` is enough to
distinguish them.

Note: Some existing error messages mention "byte constants" and some
mention "byte literals". I went with the latter here, because it's a
more correct name, as used by the Reference.

Remove a low-value comment, remove a duplicate comment, and correct a
third comment.

It deals with eight cases: ints, floats, and the six quoted types
(char/byte/strings). For ints and floats we have an early return, and
the other six types fall through to the code at the end, which makes the
function hard to read.

This commit rearranges things to avoid the early returns.

It has a single callsite, and is fairly small. The `Float` match arm
already has base-specific checking inline, so this makes things more
consistent.

The table rows were obtained via the script embedded in the page.

MCP: rust-lang/compiler-team#555

It's easy to just use `unescape_literal` + `byte_from_char`.

These lines (including the FIXME comment) were added to windows_gnu_base.rs in cf2c492 but windows_gnullvm_base.rs was not updated.  This resulted in an error `LLVM ERROR: dwo only supported with ELF and Wasm` attempting to build on aarch64-pc-windows-gnullvm.

Signed-off-by: Jeremy Drake <[email protected]>

The helper shell script has been rewritten as a helper Python script
that generates the range-based table.

…-hang, r=jackh726,wesleywiser

Avoid possible infinite  loop when next_point reaching the end of file

Fixes rust-lang#103451
If we return a span with `lo` = `hi`, `span_to_snippet` will always get `Ok("")`, which may introduce infinite loop if we don't care.

This PR make `find_width_of_character_at_span` return `width` with 1, so that `span_to_snippet` will get an `Err`.

…apes, r=wesleywiser

Fix `rustc_parse_format` spans following escaped utf-8 multibyte chars

Currently too many skips are created for char escapes that are larger than 1 byte when encoded in UTF-8, [playground:](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=c77a9dc669b69b167271b59ed2c8d88c)

```rust
fn main() {
    format!("\u{df}{a}");
    format!("\u{211d}{a}");
    format!("\u{1f4a3}{a}");
}
```
```
error[[E0425]](https://doc.rust-lang.org/stable/error-index.html#E0425): cannot find value `a` in this scope
 --> src/main.rs:2:22
  |
2 |     format!("\u{df}{a}");
  |                      ^ not found in this scope

error[[E0425]](https://doc.rust-lang.org/stable/error-index.html#E0425): cannot find value `a` in this scope
 --> src/main.rs:3:25
  |
3 |     format!("\u{211d}{a}");
  |                         ^ not found in this scope

error[[E0425]](https://doc.rust-lang.org/stable/error-index.html#E0425): cannot find value `a` in this scope
 --> src/main.rs:4:27
  |
4 |     format!("\u{1f4a3}{a}");
  |                           ^ not found in this scope
```

This reduces the number of skips to account for that

Fixes rust-lang/rust-clippy#9727

…Simulacrum

Upgrade cc for working is_flag_supported on cross-compiles

rust-lang#85806 fixed unwind v.s gcc support on later Android ndks using `is_flag_supported`. However, due to rust-lang/cc-rs#675, this didn't work properly on cross-compiles. rust-lang/cc-rs@3eeb50b fixes this, and was released in cc 1.0.74, hence the upgrade

…=matklad

Unescaping cleanups

Some code improvements, and some error message improvements.

Best reviewed one commit at a time.

r? ``@matklad``

… r=JohnTitor

Promote {aarch64,i686,x86_64}-unknown-uefi to Tier 2

MCP: rust-lang/compiler-team#555

CC ``@dvdhrm``

…ce, r=Mark-Simulacrum

Don't intra linkcheck reference

This removes the reference from the intra-doc link checks. This causes problems if any of the reference content needs to change, it causes the linkchecker to break. The reference has its own broken link check (https://github.com/rust-lang/reference/tree/master/style-check) which uses pulldown-cmark on the source to find actual broken links (instead of false-positives like this regex does).

I think the intra-doc link check could potentially be removed completely, since I think rustdoc is now checking for them well enough. However, it may serve as a decent regression check.

Update linker-plugin-lto.md to contain up to Rust 1.65

The table rows were obtained via the script embedded in the page.

fix debuginfo for windows_gnullvm_base.rs

These lines (including the FIXME comment) were added to windows_gnu_base.rs in cf2c492 but windows_gnullvm_base.rs was not updated.  This resulted in an error `LLVM ERROR: dwo only supported with ELF and Wasm` attempting to build on aarch64-pc-windows-gnullvm.

See also msys2/MINGW-packages#13921 (comment)

/cc ``@mati865`` ``@davidtwco``

r? ``@davidtwco``

…th, r=notriddle

Fix invalid background-image file name

This is a follow-up of rust-lang#101702.

Apparently the image hash was the wrong one. You can see the error in https://doc.rust-lang.org/nightly/core/primitive.u16.html?search=hello too.

I really need to check if I can adds check for resources load errors in `browser-ui-test`.

cc ``@jsha``
r? ``@notriddle``