This patch transforms functions of the form
```
fn f<Generic: AsRef<Concrete>>(arg: Generic) {
	let arg: &Concrete = arg.as_ref();
	// Code using arg
}
```
to the next form:
```
#[inline]
fn f<Generic: AsRef<Concrete>>(arg: Generic) {
	fn f_inner(arg: &Concrete) {
		// Code using arg
	}
	
	f_inner(arg.as_ref());
}
```

Therefore, most of the code is concrete and not duplicated during monomorphisation (unless inlined)
and only the tiny bit of conversion code is duplicated. This method was mentioned by @aturon in the
Conversion Traits RFC (https://github.com/rust-lang/rfcs/blame/master/text/0529-conversion-traits.md#L249) and similar techniques are not uncommon in C++ template libraries.

This patch goes to the extremes and applies the transformation even to smaller functions<sup>1</sup>
for purity of the experiment. *Some of them can be rolled back* if considered too ridiculous.

<sup>1</sup> However who knows how small are these functions are after inlining and everything.

The functions in question are mostly `fs`/`os` functions and not used especially often with variety
of argument types, so the code size reduction is rather small (but consistent). Here are the sizes
of stage2 artifacts before and after the patch:
https://gist.github.com/petrochenkov/e76a6b280f382da13c5d
https://gist.github.com/petrochenkov/6cc28727d5256dbdfed0

Note:
All the `inner` functions are concrete and unavailable for cross-crate inlining, some of them may
need `#[inline]` annotations in the future.

r? @aturon

as per #28243.

Windows's scheduler apparently has "problems" unblocking calls in the
asked for time period.

Windows's scheduler apparently has "problems" unblocking calls in the
asked for time period.

Overflows in integer pow() computations would be missed if they
preceded a 0 bit of the exponent being processed. This made
calls such as 2i32.pow(1024) not trigger an overflow.

Fixes #28012

This allows to skip the codegen for all the unneeded landing pads, reducing code size across the board by about 2-5%, depending on the crate. Compile times seem to be pretty unaffected though :-/

Unwinding across an FFI boundary is undefined behaviour, so we can mark
all external function as nounwind. The obvious exception are those
functions that actually perform the unwinding.

In addition to instruction updates I
 - changed from wget to curl, because curl is a prerequisite of rust itself
 - removed `[...]` because they're missing from so many places it would just obscure the instructions if they were all put in

r? @steveklabnik 

Technically a [breaking-change], but the broken code is useless,
like `i32<Param=()>`.

Fixes #24682

r? @EddyB 

The sort key is a (DefId, Name), which is *not* stable between
runs, so we must re-sort when loading.

Fixes #24063
Fixes #25467
Fixes #27222
Fixes #28377

r? @EddyB 

ignore severals tests under openbsd as we have disabling jemalloc under
this target.

r? @alexcrichton 

This would catch regressions of issue #28012.

There is already a corresponding impl for `std::io::Write`. This change
will make the two traits more consistent.

This changes libfmt_macros `CharIndices` iterator into `Peekable` so it can be used without `.clone()`.

Also changed some `loop match` and `match` to `while let` and `if let` respectively (mostly for readability).

This fixes the ICE, and makes it just a compiler error/warning. I'm not exactly sure that's whats wanted, so tell me if it isn't.

Technically a [breaking-change], but the broken code is useless,
like `i32<Param=()>`.

Fixes #24682

The FCP is coming to a close and 1.4 is coming out soon, so this brings in the
libs team decision for all library features this cycle.

Stabilized APIs:

* `<Box<str>>::into_string`
* `Arc::downgrade`
* `Arc::get_mut`
* `Arc::make_mut`
* `Arc::try_unwrap`
* `Box::from_raw`
* `Box::into_raw`
* `CStr::to_str`
* `CStr::to_string_lossy`
* `CString::from_raw`
* `CString::into_raw`
* `IntoRawFd::into_raw_fd`
* `IntoRawFd`
* `IntoRawHandle::into_raw_handle`
* `IntoRawHandle`
* `IntoRawSocket::into_raw_socket`
* `IntoRawSocket`
* `Rc::downgrade`
* `Rc::get_mut`
* `Rc::make_mut`
* `Rc::try_unwrap`
* `Result::expect`
* `String::into_boxed_slice`
* `TcpSocket::read_timeout`
* `TcpSocket::set_read_timeout`
* `TcpSocket::set_write_timeout`
* `TcpSocket::write_timeout`
* `UdpSocket::read_timeout`
* `UdpSocket::set_read_timeout`
* `UdpSocket::set_write_timeout`
* `UdpSocket::write_timeout`
* `Vec::append`
* `Vec::split_off`
* `VecDeque::append`
* `VecDeque::retain`
* `VecDeque::split_off`
* `rc::Weak::upgrade`
* `rc::Weak`
* `slice::Iter::as_slice`
* `slice::IterMut::into_slice`
* `str::CharIndices::as_str`
* `str::Chars::as_str`
* `str::split_at_mut`
* `str::split_at`
* `sync::Weak::upgrade`
* `sync::Weak`
* `thread::park_timeout`
* `thread::sleep`

Deprecated APIs

* `BTreeMap::with_b`
* `BTreeSet::with_b`
* `Option::as_mut_slice`
* `Option::as_slice`
* `Result::as_mut_slice`
* `Result::as_slice`
* `f32::from_str_radix`
* `f64::from_str_radix`

Closes #27277
Closes #27718
Closes #27736
Closes #27764
Closes #27765
Closes #27766
Closes #27767
Closes #27768
Closes #27769
Closes #27771
Closes #27773
Closes #27775
Closes #27776
Closes #27785
Closes #27792
Closes #27795
Closes #27797

The sort key is a (DefId, Name), which is *not* stable between
runs, so we must re-sort when loading.

Fixes #24063
Fixes #25467
Fixes #27222
Fixes #28377

There is a dead code in libsyntax/parser/parse.rs, when parsing structs.

Two functions are involved:

* [parse_item_struct](https://github.com/rust-lang/rust/blob/cd9c9f048f6aa0be091cd9835771ba0712bead4e/src/libsyntax/parse/parser.rs#L4691)
* [parse_tuple_struct_body](https://github.com/rust-lang/rust/blob/cd9c9f048f6aa0be091cd9835771ba0712bead4e/src/libsyntax/parse/parser.rs#L4769)

The problem is that both functions handle the case with unit structs. But because
`parse_tuple_struct_body` is called from `parse_item_struct`, it never faces
this case.

This PR removes unit struct case from `parse_tuple_struct_body` function. I tested with `make -j8 check-statge1`.

Commit 9104a902 fixed the generated
files, but that change would be lost (or require additional manual
intervention) if they are re-generated of if new architectures are
added.

cc #28273

There is already a corresponding impl for `std::io::Write`. This change
will make the two traits more consistent.

This is something that I wish I had when I started contributing to Rust (not that long ago :). I plan on writing a manual for bors and the rust testing setup too, if there isn't one already.

- Headlines begin at 1st level now like the rest of the book
- All Headlines a blank line above and below
- Fix links in this chapter's TOC

r? @steveklabnik 

ignore severals tests under openbsd as we have disabling jemalloc under
this target.

and regenerate the platform intrinsics source files.

The style `[name][]` does not work with Pandoc, whereas `[name]` does. I hope hoedown accepts this as well.

r? @steveklabnik 

The style `[name][]` does not work with Pandoc, whereas `[name]` does.
I hope hoedown accepts this as well.

- Headlines begin at 1st level now like the rest of the book
- All Headlines a blank line above and below
- Fix links in this chapter's TOC

Commit 9104a902 fixed the generated
files, but that change would be lost (or require additional manual
intervention) if they are re-generated of if new architectures are
added.

cc #28273

Redirect stdout on the python bogosity detector. This is printing
pwd to the terminal currently.

Reformat the bogus python/cmake messages so they format correctly.
echo does not always escape newlines (it doesn't here), and multiline
strings don't whitespace munch.

r? @alexcrichton