Use `TokenTree`s in lhs of macros
Remove `Matcher`s
Workaround to have doc comments desugared only in macros
Properly escape paths to executables. Fixes #18632.
Correct building documenation with Pandoc and TeX on Windows.
Implement Index/IndexMut for [T]

Closes #16529
Make EnumSet not silently corrupt data.

Assert at run time instead. Fixes #13756.

I’d rather have this be detected at compile-time, but I don’t know how to do that.
EnumSet assertion: better error message.
Add example impl in CLike docs. Fix 13752.
libs: add Deref, DerefMut impls for references, fixing a bug in compiler in the process that was blocking this.

Fixes #18621.
Add and update tests
Add `ast::SequenceRepetition`
auto merge of #18698 : japaric/rust/index, r=alexcrichton

Closes #16529

r? @aturon
auto merge of #18714 : nikomatsakis/rust/issue-18621-deref-for-refs, r=aturon

libs: add Deref, DerefMut impls for references, fixing a bug in compiler in the process that was blocking this.

r? @aturon
Do not put double quotes around empty variables.
auto merge of #18721 : SimonSapin/rust/safer-enumset, r=alexcrichton

Assert at run time instead. Fixes #13756.

I’d rather have this be detected at compile-time, but I don’t know how to do that.
auto merge of #17830 : pczarn/rust/interp_tt, r=pnkfelix

Closes #14197

Removes the `matchers` nonterminal.

If you're using `$foo:matchers` in a macro, write `$foo:tt` instead.

[breaking-change]
auto merge of #18673 : VHaravy/rust/issue-18632, r=alexcrichton

1. Introduce `putpathvar` function that prints variable shell-quoted by using `%q` format specifier. This function is used within `probe` to save the result into `config.tmp`.
2. Removes search-and-replace pattern that transforms `\` into `/` as it messes up shell-quoted strings.
Make TyTrait embed a `TraitRef`, so that when we extend TraitRef, it naturally carries over to object types.

I wanted to embed an `Rc<TraitRef>`, but I was foiled by the current
static rules, which prohibit non-Sync values from being stored in
static locations. This means that the constants for `ty_int` and so
forth cannot be initialized.
Update parser with `for` syntax