…a file

This alters the stdio code on Windows to always call `GetStdHandle` whenever the
stdio read/write functions are called as this allows us to track changes to the
value over time (such as if a process calls `SetStdHandle` while it's running).

Closes rust-lang#40490

This "on-demand" task both checks for errors and computes the custom
unsized kind, if any. This task is only defined on impls of
`CoerceUnsized`; invoking it on any other kind of impl results in a bug.
This is just to avoid having an `Option`, could easily be changed.

Top-down, top-down!

There are now 3 queries:

- inherent_impls(def-id): for a given type, get a `Rc<Vec<DefId>>` with
  all its inherent impls. This internally uses `crate_inherent_impls`,
  doing some hacks to keep the current deps (which, btw, are not clearly
  correct).
- crate_inherent_impls(crate): gathers up a map from types
  to `Rc<Vec<DefId>>`, touching the entire krate, possibly generating
  errors.
- crate_inherent_impls_overlap_check(crate): performs overlap checks
  between the inherent impls for a given type, generating errors.

I'm not really sure what we want the cadence here to be. We'll at the very least
update the Cargo submodule right before all releases, but otherwise I figured we
could just do it whenever needed or otherwise weekly (or something like that).

In any case, I don't have a super strong particular reason to do this, it's just
been a week or so since the release!

Select 3 random points instead of just 1.
Also the code now compiles on 16bit architectures.

The docs need to be built with the rustbuild feature so the correct
stability attributes (rustc_private) get applied.

This makes sure RFC links point to the RFC text not the pull request.

It looks like the 6.3.0 MinGW comes with a gdb which has issues (rust-lang#40184) that an
attempted workaround (rust-lang#40777) does not actually fix (rust-lang#40835). The original
motivation for upgradin MinGW was to fix build flakiness (rust-lang#40546) due to newer
builds not exhibiting the same bug, so let's hope that 6.2.0 isn't too far back
in time and still contains the fix we need.

Closes rust-lang#40835

Update libc to 0.2.21

Update to include android aarch64 and x86 improvements.

…uron

std: Don't cache stdio handles on Windows

This alters the stdio code on Windows to always call `GetStdHandle` whenever the
stdio read/write functions are called as this allows us to track changes to the
value over time (such as if a process calls `SetStdHandle` while it's running).

Closes rust-lang#40490

…seyfried

Improve `InternedString` usability

…ed-info, r=eddyb

on-demand-ify `custom_coerce_unsized_kind` and `inherent-impls`

This "on-demand" task both checks for errors and computes the custom unsized kind, if any. This task is only defined on impls of `CoerceUnsized`; invoking it on any other kind of impl results in a bug. This is just to avoid having an `Option`, could easily be changed.

r? @eddyb

save-analysis: allow clients to get data directly without writing to a file.

…ichton

Update cargo submodule

I'm not really sure what we want the cadence here to be. We'll at the very least
update the Cargo submodule right before all releases, but otherwise I figured we
could just do it whenever needed or otherwise weekly (or something like that).

In any case, I don't have a super strong particular reason to do this, it's just
been a week or so since the release!

… r=nrc

macros: fix ICE on some nested macro definitions

Fixes rust-lang#40770.
r? @nrc

Don't stutter in operator trait descriptions

Fixes first item on rust-lang#29365.

r? @steveklabnik

Link ParseBoolError to from_str method of bool

Referencing task in rust-lang#29375. Sorry for not opening another branch on my fork for this. Was working on this early this morning and forgot to branch off master

…steveklabnik

FromStr implementation example

Referencing rust-lang#29375. Added example implementation of FromStr trait to API Documentation

…eklabnik

rustdoc to accept `#` at the start of a markdown file rust-lang#40560

This may be a bit odd if `#` and `%` lines are mixed up, but that's not something I've found while doing my search and replace.

libcore: fix compilation on 16bit target (MSP430).

Since PR rust-lang#40601 has been merged, libcore no longer compiles on MSP430.
The reason is this code in `break_patterns`:
```rust
 let mut random = len;
 random ^= random << 13;
 random ^= random >> 17;
 random ^= random << 5;
 random &= modulus - 1;
```
It assumes that `len` is at least a 32 bit integer.
As a workaround replace `break_patterns` with an empty function for 16bit targets.

cc @stjepang
cc @alexcrichton

…=steveklabnik

Fix typo in char::to_uppercase documentation

Original documentation appears to have been copied from `char::to_lowercase` in a manner that made it imply that `char::to_uppercase` actually mapped unicode characters to their **lowercase** equivalent.

change string references in asciiext

…lutions, r=nrc

bugfix: finalize resolutions of macros in trait positions

Fixes rust-lang#40845.
r? @nrc

…alexcrichton

rustbuild: Fix compiler docs again

The docs need to be built with the rustbuild feature so the correct
stability attributes (rustc_private) get applied.

r? @alexcrichton

Fix broken Markdown and bad links in the error index

This makes sure RFC links point to the RFC text not the pull request.

r? @steveklabnik

…elb1

appveyor: Downgrade MinGW to 6.2.0

It looks like the 6.3.0 MinGW comes with a gdb which has issues (rust-lang#40184) that an
attempted workaround (rust-lang#40777) does not actually fix (rust-lang#40835). The original
motivation for upgradin MinGW was to fix build flakiness (rust-lang#40546) due to newer
builds not exhibiting the same bug, so let's hope that 6.2.0 isn't too far back
in time and still contains the fix we need.

Closes rust-lang#40835