update master

Use back-ticks instead of quotation marks in docs for the block comment
variant of TokenKind.

Fix missing punctuation

…ing_ones, r=Amanieu

stabilize leading_trailing_ones

This PR stabilizes the `leading_trailing_ones` feature. It's been available on nightly since the start of the year, and hasn't had any issues since. It seems unlikely we'll want to change this, so following up on @djc's suggestion in rust-lang#57969 (comment) I'd like to put forward this PR to stabilize the feature and make it part of `1.46.0`. Thanks!

cc/ @djc @rust-lang/libs

…LukasKalbertodt

Remap Windows ERROR_INVALID_PARAMETER to ErrorKind::InvalidInput from Other

I don't know if this is acceptable or how likely it is to break existing code, but it seem to me ERROR_INVALID_PARAMETER "The parameter is incorrect" should map to ErrorKind::InvalidInput "A parameter was incorrect". Previously this value fell through to ErrorKind::Other.

I can't speak for anyone but myself, but I instinctively thought it would be InvalidInput.

…Simulacrum

Remove defunct `-Z print-region-graph`

…iplett

Fix comma in debug_assert! docs

…thewjasper

Edit cursor.prev() method docs in lexer

Fix missing punctuation

…r=jonas-schievink

Fix markdown rendering in librustc_lexer docs

Use back-ticks instead of quotation marks in docs for the block comment variant of TokenKind.

## [Before](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_lexer/enum.TokenKind.html#variant.BlockComment) and after

<img width="1103" alt="Screen Shot 2020-06-28 at 1 22 30 PM" src="https://user-images.githubusercontent.com/19642016/85957562-446a8380-b943-11ea-913a-442cf7744083.png">

<img width="1015" alt="Screen Shot 2020-06-28 at 1 28 29 PM" src="https://user-images.githubusercontent.com/19642016/85957566-4af8fb00-b943-11ea-8fef-a09c1d586772.png">

## Question

For visual consistency, should we use back-ticks throughout the docs for these enum variants?