std: Remove bump_box_refcount. Deprecated and unused. Deprecused.
std: Doc typos
std: Reorder definitions in cast

Prioritize `transmute` and `forget`.
std: Change names of transmute's type parameters

from L, G to T, U. I don't know what L and G mean.
T, U easier to understand.
std: Small doc tweaks
Change the biguint documentation example to reflect deprecated owned vector
std: Mark timeout methods experimental

This was intended as part of the I/O timeouts commit, but it was mistakenly
forgotten. The type of the timeout argument is not guaranteed to remain constant
into the future.
Correct attribute grammar in reference manual
Fix false lint warnings in match arms with multiple patterns

fixing #13866
auto merge of #14019 : brson/rust/docs, r=alexcrichton

Just small bits of polish.
auto merge of #14025 : tbrooks8/rust/big_uint_doc, r=alexcrichton

I changed the documentation for the BigUint to reflection the deprecation of ~[T] in favor of Vec<T>.
auto merge of #14035 : alexcrichton/rust/experimental, r=huonw

This was intended as part of the I/O timeouts commit, but it was mistakenly
forgotten. The type of the timeout argument is not guaranteed to remain constant
into the future.
auto merge of #14043 : sanxiyn/rust/attr-reference, r=alexcrichton

Attribute grammar in reference manual allowed `#[foo, bar]`, which does not match parser behavior.

Also rename nonterminals to match parser code.

Fix #13825.
auto merge of #14044 : hirschenberger/rust/lint_mut_match, r=alexcrichton

fixing #13866