Update RELEASES.txt

Fix Typos
Refactored VecPerParamSpace to hide exposure of `Vec` representation.

This basically meant changing the interface so that no borrowed `&Vec`
is exposed, by hiding `fn get_vec` and `fn get_mut_vec` and revising
`fn all_vecs`.

Instead, clients should use one of the other methods; `get_slice`,
`pop`, `truncate`, `replace`, `push_all`, or `is_empty_in`, which
should work for any case currently used in rustc.
Revise `VecPerParamSpace` to use a one Vec rather than three.

In my informal measurements, this brings the peak memory usage when
building librustc from 1662M down to 1502M.  Since 1662 - 1502 = 160,
this may not recover the entirety of the observed memory regression
(250M) from PR #14604.  (However, according to my local measurements,
the regression when building librustc was more like 209M, so perhaps
this will still recover the lions share of the lost memory.)
auto merge of #15284 : apoelstra/rust/bitv-methods, r=cmr

The types `Bitv` and `BitvSet` are badly out of date. This PR:
- cleans up the code (primarily, simplifies `Bitv` and implements `BitvSet` in terms of `Bitv`)
- implements several new traits for `Bitv`
- adds new functionality to `Bitv` and `BitvSet`
- replaces internal iterators with external ones
- updates documentation
- minor bug fixes

This is a significantly souped-up version of PR #15139 and is the result of the discussion there.
auto merge of #15414 : zsiciarz/rust/patch-1, r=alexcrichton
auto merge of #15418 : pnkfelix/rust/fsk-revise-VecPerParamSpace, r=pcwalton

In my informal measurements, this brings the peak memory usage when
building librustc from 1662M down to 1502M.  Since 1662 - 1502 = 160,
this may not recover the entirety of the observed memory regression
(250M) from PR #14604.  (However, according to my local measurements,
the regression when building librustc was more like 209M, so perhaps
this will still recover the lions share of the lost memory.)
libcore: Fix Items iterator for zero sized types.
auto merge of #15442 : luqmana/rust/odp, r=pnkfelix

Inadvertently changed the order in which destructors ran in certain cases with #15076.

Fixes #15438.
auto merge of #15427 : aochagavia/rust/parse, r=pcwalton
Fix #15453
auto merge of #15428 : phildawes/rust/master, r=huonw

Fix small bug introduced in e38cb972dcf: PatIdent span was incorrect
because self.last_span was being used before the ident token was
parsed.
Improved example in the Guide

Fixes https://github.com/rust-lang/rust/issues/15452
auto merge of #15429 : kballard/rust/vim_tab_conventions, r=pcwalton
auto merge of #15431 : iliekturtles/rust/13279-error-msg-order, r=pcwalton

Moved note after error to reduce confusion when the pair appears in the
middle of other errors. Closes #13279.
Added num::Signed implementation to Ratio (squashed)
rustc: Remove CrateId and all related support

This commit removes all support in the compiler for the #[crate_id] attribute
and all of its derivative infrastructure. A list of the functionality removed is:

* The #[crate_id] attribute no longer exists
* There is no longer the concept of a version of a crate
* Version numbers are no longer appended to symbol names
* The --crate-id command line option has been removed

To migrate forward, rename #[crate_id] to #[crate_name] and only the name of the
crate itself should be mentioned. The version/path of the old crate id should be
removed.

For a transitionary state, the #[crate_id] attribute is still accepted if
the #[crate_name] is not present, but it is warned about if it is the only
identifier present.

RFC: 0035-remove-crate-id
[breaking-change]
rustc: Add a new codegen flag, -C metadata=foo

This metadata is used to drive the hash of all symbols in a crate. The flag can
be specified a multiple number of times

RFC: 0035-remove-crate-id
rustc: Modify crate loading to ignore versions

This commit modifies crate loading to purely work off a `crate_name` and nothing
else. This commit also changes the patterns recognized from `lib<foo>-*` to
`lib<foo>*` to accomodate the future renamings of output files.

RFC: 0035-remove-crate-id
Add #[crate_name] attributes as necessary
rustc: Stop putting hashes in filenames by default

The compiler will no longer insert a hash or version into a filename by default.
Instead, all output is simply based off the crate name being compiled. For
example, a crate name of `foo` would produce the following outputs:

* bin => foo
* rlib => libfoo.rlib
* dylib => libfoo.{so,dylib} or foo.dll
* staticlib => libfoo.a

The old behavior has been moved behind a new codegen flag,
`-C extra-filename=<hash>`. For example, with the "extra filename" of `bar` and
a crate name of `foo`, the following outputs would be generated:

* bin => foo (same old behavior)
* rlib => libfoobar.rlib
* dylib => libfoobar.{so,dylib} or foobar.dll
* staticlib => libfoobar.a

The makefiles have been altered to pass a hash by default to invocations of
`rustc` so all installed rust libraries will have a hash in their filename. This
is done because the standard libraries are intended to be installed into
privileged directories such as /usr/local. Additionally, it involves very few
build system changes!

RFC: 0035-remove-crate-id
[breaking-change]