The "read more" sentence formatted "object safety" as inline code
instead of providing a link to more information.  This PR adds a link
to the Reference about this matter, as well as the page regarding trait
objects.

…d Vec

To remind people like me who forget about it and send PRs to make them different, and to (probably) get a test failure if the code is changed to no longer uphold it.

Added the --temps-dir option

Fixes rust-lang#10971.

The new `--temps-dir` option puts intermediate files in a user-specified directory. This provides a fix for the issue where parallel invocations of rustc would overwrite each other's intermediate files.

No files are kept in the intermediate directory unless `-C save-temps=yes`.

If additional files are specifically requested using `--emit asm,llvm-bc,llvm-ir,obj,metadata,link,dep-info,mir`, these will be put in the output directory rather than the intermediate directory.

This is a backward-compatible change, i.e. if `--temps-dir` is not specified, the behavior is the same as before.

Fix span calculation in format strings

This pull request fixes rust-lang#86085. The ICE described there is due to an error in the span calculation inside format strings, if the format string is the result of a macro invocation:
```rust
fn main() {
    format!(concat!("abc}"));
}
```
currently produces:
```
error: invalid format string: unmatched `}` found
 --> test.rs:2:17
  |
2 |     format!(concat!("abc}"));
  |                 ^ unmatched `}` in format string
```
which is obviously incorrect. This happens because the span of the entire `concat!()` is combined with the _relative_ location of the unmatched `` `}` `` in the _result_ of the macro invocation (i.e. 4).

In rust-lang#86085, this has led to a span that starts or ends in the middle of a multibyte character, but the root cause was the same. This pull request fixes the problem.

…nytm

Mention the `Borrow` guarantee on the `Hash` implementations for Arrays and `Vec`

To remind people like me who forget about it and send PRs to make them different, and to (probably) get a test failure if the code is changed to no longer uphold it.

…d, r=kennytm

Link reference in `dyn` keyword documentation

The "read more" sentence formatted "object safety" as inline code
instead of providing a link to more information.  This PR adds a link
to the Reference about this matter, as well as the page regarding trait
objects.

---

We could also put these links in the very first line (instead of the link to the
Book) and in the first paragraph which mentions the "object safe" requirement.
Personally, I think it's good to keep the link to the Book up-front as it's more
accessible than the Reference.

…s, r=petrochenkov

Mention rust-lang#79078 on compatibility notes of 1.52

Closes rust-lang#85854
r? `@petrochenkov`

Do not emit invalid suggestions on multiple mutable borrow errors

Fixes rust-lang#85581

…_predicates, r=oli-obk

Remove `projection_ty_from_predicates`

Fixes rust-lang#86350
r? `@oli-obk`

Remove invalid suggestions for assoc consts on placeholder type error

Fixes rust-lang#82158
This also moves some tests to typeck.
r? `@estebank`

… r=jsha

Add missing backslashes to prevent unwanted backlines in rustdoc HTML

Just adding some forgotten backslashes.

r? `@jsha`

Typo correction: s/is/its