If the compiler docs aren't going to include the test crate then it may as well be included with std.

This commit adds even more pessimization to use the cached `TokenStream` inside
of an AST node. As a reminder the `proc_macro` API requires taking an arbitrary
AST node and transforming it back into a `TokenStream` to hand off to a
procedural macro. Such functionality isn't actually implemented in rustc today,
so the way `proc_macro` works today is that it stringifies an AST node and then
reparses for a list of tokens.

This strategy unfortunately loses all span information, so we try to avoid it
whenever possible. Implemented in rust-lang#43230 some AST nodes have a `TokenStream`
cache representing the tokens they were originally parsed from. This
`TokenStream` cache, however, has turned out to not always reflect the current
state of the item when it's being tokenized. For example `#[cfg]` processing or
macro expansion could modify the state of an item. Consequently we've seen a
number of bugs (rust-lang#48644 and rust-lang#49846) related to using this stale cache.

This commit tweaks the usage of the cached `TokenStream` to compare it to our
lossy stringification of the token stream. If the tokens that make up the cache
and the stringified token stream are the same then we return the cached version
(which has correct span information). If they differ, however, then we will
return the stringified version as the cache has been invalidated and we just
haven't figured that out.

Closes rust-lang#48644
Closes rust-lang#49846

Previously, generate-deriving-span-tests.py would regenerate all the tests anew, even if they hadn't changed. This creates unnecessary diffs that only change the copyright year. Now we check to see if any of the content of the test has changed before generating the new one.

This includes rust-lang/cargo#5353,
which we might want to test via opt-in in the wild

This makes it consistent with TypeParameterDef.

Some modules were still using the deprecated `allocator` module, use the
`alloc` module instead.

Some modules were using `super` while it's not needed.

Some modules were more or less ordering them, and other not, so the
latter have been modified to match the others.

Update Cargo

This includes rust-lang/cargo#5353, which we  want to test via opt-in in the wild.

This'll break RLS, the fix is rust-lang/rls#822

…r=nrc

proc_macro: Avoid cached TokenStream more often

This commit adds even more pessimization to use the cached `TokenStream` inside
of an AST node. As a reminder the `proc_macro` API requires taking an arbitrary
AST node and transforming it back into a `TokenStream` to hand off to a
procedural macro. Such functionality isn't actually implemented in rustc today,
so the way `proc_macro` works today is that it stringifies an AST node and then
reparses for a list of tokens.

This strategy unfortunately loses all span information, so we try to avoid it
whenever possible. Implemented in rust-lang#43230 some AST nodes have a `TokenStream`
cache representing the tokens they were originally parsed from. This
`TokenStream` cache, however, has turned out to not always reflect the current
state of the item when it's being tokenized. For example `#[cfg]` processing or
macro expansion could modify the state of an item. Consequently we've seen a
number of bugs (rust-lang#48644 and rust-lang#49846) related to using this stale cache.

This commit tweaks the usage of the cached `TokenStream` to compare it to our
lossy stringification of the token stream. If the tokens that make up the cache
and the stringified token stream are the same then we return the cached version
(which has correct span information). If they differ, however, then we will
return the stringified version as the cache has been invalidated and we just
haven't figured that out.

Closes rust-lang#48644
Closes rust-lang#49846

…r=alexcrichton

Cross-compile builder to Windows for PRs on Travis

I chose a completely arbitrary windows target here (I have no idea what's best, we could do multiple -- they are relatively fast).

…☹, r=nrc

Don't inject clippy into rls on stable/beta

as discussed at the all-hands

…eklabnik,QuietMisdreavus,frewsxcv,GuillaumeGomez

Add docs for the test crate with the std docs

If the compiler docs aren't going to include the test crate then it may as well be included with std.

Fixes rust-lang#49388

…-usability, r=nikomatsakis

Ignore copyright year when generating deriving span tests

Previously, generate-deriving-span-tests.py would regenerate all the tests anew, even if they hadn't changed. This creates unnecessary diffs that only change the copyright year. Now we check to see if any of the content of the test has changed before generating the new one.

…st-without-rpath, r=Mark-Simulacrum

Fix test failure in src/tools/rustdoc-themes when rust.rpath = false

See rust-lang#49907

…tring, r=petrochenkov

Use InternedString rather than Name for RegionParameterDef

This makes it consistent with `TypeParameterDef`.

[doc] note the special type inference handling for shift ops

This adds a note to the docs about the difference between the shift ops and the corresponding trait methods when it comes to type inference.

…ennytm

improve Atomic*::fetch_update docs

This clarifies that fetch_update *always* returns the previous value, either as `Ok(_)` or `Err(_)`, depending on whether the supplied update function returned `Some(_)` or `None`.

Remove -Zmiri debugging option

Cleanup liballoc use statements

Some modules were still using the deprecated `allocator` module, use the
`alloc` module instead.

Some modules were using `super` while it's not needed.

Some modules were more or less ordering them, and other not, so the
latter have been modified to match the others.

Add to_bytes and from_bytes to primitive integers

Discussion issue turned tracking issue: rust-lang#49792

…ures, r=GuillaumeGomez

add target features when extracting and running doctests

When rendering documentation, rustdoc will happily load target features into the cfg environment from the current target, but fails to do this when doing anything with doctests. This would lead to situations where, thanks to rust-lang#48759, functions tagged with `#[target_feature]` couldn't run doctests, thanks to the automatic `#[doc(cfg(target_feature = "..."))]`.

Currently, there's no way to pass codegen options to rustdoc that will affect its rustc sessions, but for now this will let you use target features that come default on the platform you're targeting.

Fixes rust-lang#49723