Rollup merge of #129675 - lolbinarycat:bufreader_peek_unsized, r=work…

Rollup merge of #129675 - lolbinarycat:bufreader_peek_unsized, r=work… · patricklam/verify-rust-std@9138bd1

Original file line number	Diff line number	Diff line change
`@@ -94,7 +94,9 @@ impl<R: Read> BufReader<R> {`
`94`	`94`	`pub fn with_capacity(capacity: usize, inner: R) -> BufReader<R> {`
`95`	`95`	`BufReader { inner, buf: Buffer::with_capacity(capacity) }`
`96`	`96`	`}`
	`97`	`+}`
`97`	`98`
	`99`	`+impl<R: Read + ?Sized> BufReader<R> {`
`98`	`100`	/// Attempt to look ahead `n` bytes.
`99`	`101`	`///`
`100`	`102`	/// `n` must be less than `capacity`.