Add links to forums in README.md, including discuss.rust-lang.org
Test fixes from the rollup
auto merge of #17127 : alexcrichton/rust/rollup, r=alexcrichton
Fix snapshot.py for win64
Fix naming of windows installer
Implement tuple and tuple struct indexing

This allows code to access the fields of tuples and tuple structs:

    let x = (1i, 2i);
    assert_eq!(x.1, 2);

    struct Point(int, int);
    let origin = Point(0, 0);
    assert_eq!(origin.0, 0);
    assert_eq!(origin.1, 0);
Avoid ever constructing cyclic types in the first place, rather than detecting them in resolve. This simplifies logic elsewhere in the compiler. cc #5527
Be explicit with rustdoc.

I missed some annotations, and some were in a different style.
Add section about Str trait
auto merge of #16662 : pczarn/rust/format-fmtstr-opt, r=brson

Based on an observation that strings and arguments are always interleaved, thanks to #15832. Additionally optimize invocations where formatting parameters are unspecified for all arguments, e.g. `"{} {:?} {:x}"`, by emptying the `__STATIC_FMTARGS` array. Next, `Arguments::new` replaces an empty slice with `None` so that passing empty `__STATIC_FMTARGS` generates slightly less machine code when `Arguments::new` is inlined. Furthermore, formatting itself treats these cases separately without making redundant copies of formatting parameters.

All in all, this adds a single mov instruction per `write!` in most cases. That's why code size has increased.
Prefer lualatex, xelatex, pdflatex, in that order. #12804
librustc: Obsolete the old external crate renaming syntax.

Instead of `extern crate foo = bar`, write `extern crate bar as foo`.
Instead of `extern crate baz = "quux"`, write `extern crate "quux" as
baz`.

Closes #16461.

[breaking-change]
auto merge of #16824 : steveklabnik/rust/string_guide_improvements, r=alexcrichton

A few steps toward https://github.com/rust-lang/rust/issues/15994
auto merge of #17048 : pcwalton/rust/remove-old-import-renaming-syntax, r=brson

Instead of `extern crate foo = bar`, write `extern crate bar as foo`.
Instead of `extern crate baz = "quux"`, write `extern crate "quux" as
baz`.

Closes #16461.

[breaking-change]

r? @brson
Don't ICE on macros with -Z show-span

Closes #17115
auto merge of #17108 : steveklabnik/rust/explicitness, r=alexcrichton

I missed some annotations, and some were in a different style.
micro-optimize dynamic allocation alignment

Previously, some parts of this optimization were impossible because the
alignment passed to the free function was not correct. That was fully
fixed by #17012.

Closes #17092
implement sized deallocation

Closes #13994
Add unnecessary_import_braces lint.

The lint checks any unnecessary braces around one imported item like
`use std::num::{abs};`.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
auto merge of #17095 : thestinger/rust/alloc, r=alexcrichton

Previously, some parts of this optimization were impossible because the
alignment passed to the free function was not correct. That was fully
fixed by #17012.

Closes #17092