is_unsafe_place only filters out statics in the rhs, not the lhs. Since
it's possible to reach that 'Place::Static', we handle statics the same
way as we do locals.

Fixes rust-lang#47789

Currently ', " and \ are escaped as \', \" and \\ respectively. This
leads to confusing messages such as `error: unknown start of token: \\`
when encountering a single backslash.

Fix by emitting printable ASCII characters directly. This will still
escape \r, \n, \t and Unicode characters.

Fixes rust-lang#47902

The `exchange_free` lang item is gone in favour of `box_free` [1].

Some warnings are also fixed by this commit.

[1]: rust-lang@ca115dd

The current `f32|f64.to_degrees` implementation uses a division to calculate 180/π, which causes a loss of precision. Using a constant is still not perfect (implementing a maximally-precise algorithm would come with a high performance cost), but improves precision with a minimal change.

Sometimes the parser attempts to synthesize spans from within a macro
context with the span for the captured argument, leading to non-sensical
spans with very bad output. Given that an incorrect span is worse than
a partially incomplete span, when detecting this situation return only
one of the spans without mergin them.

Document the size of bool

…uggest removing value from `break` when invalid When attempting to use `break` with a value in a type of loop where it'd be invalid (any non-`loop`), suggest using `break` on its own. Close rust-lang#34359.

…ove dead code The Clone impl makes the lint ignore the type.

…sakis Fix ICE when assigning references to a static mut with NLL is_unsafe_place only filters out statics in the rhs, not the lhs. Since it's possible to reach that 'Place::Static', we handle statics the same way as we do locals. Fixes rust-lang#47789

…r-msg, r=petrochenkov Improve char escaping in lexer messages Currently ', " and \ are escaped as \', \" and \\ respectively. This leads to confusing messages such as `error: unknown start of token: \\` when encountering a single backslash. Fix by emitting printable ASCII characters directly. This will still escape \r, \n, \t and Unicode characters. Fixes rust-lang#47902

…ms box example code The `exchange_free` lang item is gone in favour of `box_free` [1]. Some warnings are also fixed by this commit. [1]: rust-lang@ca115dd

…ppe Use constant for 180/π in to_degrees The current `f32|f64.to_degrees` implementation uses a division to calculate `180/π`, which causes a loss of precision. Using a constant is still not perfect (implementing a maximally-precise algorithm would come with a high performance cost), but improves precision with a minimal change. As per the discussion in rust-lang#29944, this fixes rust-lang#29944 (the costs of improving the precision further would not outweigh the gains).

…s Minimize weird spans involving macro context Sometimes the parser attempts to synthesize spans from within a macro context with the span for the captured argument, leading to non-sensical spans with very bad output. Given that an incorrect span is worse than a partially incomplete span, when detecting this situation return only one of the spans without merging them. Fix rust-lang#32072, rust-lang#47778. CC rust-lang#23480.

…etMisdreavus Fix ugly hover in sidebar In the sidebar, the elements under `Structs`, `Enums`... have an ugly hover if they're not selected. This fixes it. r? @QuietMisdreavus

The comment referred to a variable using an incorrect name. (it has probably been renamed since the comment was written, or the comment was copied elsewhere - I noted the example in libcore has the `tmp` name for the temporary variable.)

copy_nonoverlapping example: Fixed typo

The comment referred to a variable using an incorrect name. (it has probably been renamed since the comment was written, or the comment was copied elsewhere - I noted the example in libcore has the `tmp` name for the temporary variable.)