Point at the immutable local variable when trying to modify one of its
fields.

Given a file:

```rust
struct Foo {
    pub v: Vec<String>
}

fn main() {
    let f = Foo { v: Vec::new() };
    f.v.push("cat".to_string());
}
```

present the following output:

```
error: cannot borrow immutable field `f.v` as mutable
 --> file.rs:7:13
  |
6 |    let f = Foo { v: Vec::new() };
  |        - this should be `mut`
7 |    f.v.push("cat".to_string());
  |    ^^^

error: aborting due to previous error
```

Change the wording of mutable borrow on immutable binding from "this
should be `mut`" to "consider changing this to `mut f`".

See rust-lang/rfcs#1414.

Updates rust-lang#38865.

It does not seem valuable to always evaluate the right-hand side here.

This seems to match other uses of "be accessed" in the document.

…rate::` path.

… to be more precise.

Fixes issue rust-lang#40408.

The name of the variable used in the example is `path`, not `os_str`.

Add feature gate for rvalue-static-promotion

Probably needs more tests (which ones?) and there may be other things that need to be done. Also not sure whether the version that introduces the flag is really `1.15.1`.

See rust-lang/rfcs#1414.

Updates rust-lang#38865.

…rner

Point to let when modifying field of immutable variable

Point at the immutable local variable when trying to modify one of its
fields.

Given a file:

```rust
struct Foo {
    pub v: Vec<String>
}

fn main() {
    let f = Foo { v: Vec::new() };
    f.v.push("cat".to_string());
}
```

present the following output:

```
error: cannot borrow immutable field `f.v` as mutable
 --> file.rs:7:13
  |
6 |    let f = Foo { v: Vec::new() };
  |        - this should be `mut`
7 |    f.v.push("cat".to_string());
  |    ^^^

error: aborting due to previous error
```

Fix rust-lang#27593.

Remove unused param from bootstrap::clean::rm_rf

None

…wsxcv

Fix const not displayed in rustdoc

Fixes rust-lang#40331.

r? @rust-lang/docs

…ion, r=nrc

macros: fix regression with `include!()`

Fixes rust-lang#40469, a regression when `include!()`ing a `macro_rules!` containing `$crate`.
r? @nrc

…excrichton

Add a test for issue 34571

Closes rust-lang#34571.

… r=nagisa

Parse 0e+10 as a valid floating-point literal

Fixes issue rust-lang#40408.

documented order of conversion between u32 an ipv4addr

This fixes rust-lang#40118

…uillaumeGomez

minor wording tweak to slice::{as_ptr, as_mut_ptr}

Per rust-lang#37334, the slice-as-pointer methods mentioned that "modifying the slice may cause its buffer to be reallocated", when in fact modifying the *slice* itself would cause no such change. (It is a borrow, after all!) This is a tweak to the wording of that line to stress it's the *collection* that could cause the buffer to be reallocated.

r? @steveklabnik

Fix typo in mutex.rs docs

This seems to match other uses of "be accessed" in the document.

…sfackler

Fix a spelling error in HashMap documentation, and slightly reword surrounding text for precision

Noticed while reading docs just now.

It's possible that the prior wording *meant* to state that the seed's randomness depends on the exact instant that the system RNG was created, I guess.  But unless there's an API guarantee that this is the case, the wording seems over-precise.  Is there a formal API guarantee that would forbid, say, the system RNG from generating all output using the Intel RDRAND instruction?  I don't think the quality of output in that case would depend on when the RNG was created.  Yet it seems to me like it could well be a valid source of randomness when computing the initial seed.

For that reason, tying the randomness of the seed, to the quality of the RNG's output *at the precise instant the seed is computed*, seems less confining.  That instantaneous quality level could be determined by the quality at the instant the RNG was created -- but instantaneous quality need not be low for that precise reason.

…r=frewsxcv

Add mention of None as possible return. Closes rust-lang#40435.

This commit adds a small mention to some methods that None is returned when the slice is empty.

Fix a typo in path.rs docs

The name of the variable used in the example is `path`, not `os_str`.