This cleans up the build.rs of `libc-test` for apple targets.

I wanted to update the docker containers of some targets so that we can start
testing newer currently-skipped APIs properly, but it is impossible to figure
out which headers and APIs are skipped for each target.

This PR separates the testing of apple targets into its own self-contained
function. This allows seeing exactly which headers are included, and which items
are skipped. A lot of work will be required to separate the testing of all major
platforms and make the script reasonable.

During the clean up, I discovered that, at least for apple targets, deprecated
but not removed APIs are not tested. I re-enabled testing for those, and fixed
`daemon`, which was not properly linking its symbol. I also added the
`#[deprecated]` attribute to the `#[deprecated]` APIs of the apple targets. The
attribute is available since Rust 1.9.0 and the min. Rust version we support is
Rust 1.13.0.

Many other APIs are also currently not tested "because they are weird" which I
interpret as "the test failed for an unknown reason", as a consequence:

* the signatures of execv, execve, and execvp are incorrect (see
  https://github.com/rust-lang/libc/issues/1272)

* the `sig_t` type is called `sighandler_t` in libc for some reason:
  https://github.com/rust-lang/libc/issues/1273

This probably explains why some other things, like the
`sa_handler`/`sa_sigaction` fields of `sigaction` were skipped. The field is
actually a union, which can be either a `sig_t` for the `sa_handler` field, or
some other type for the `sa_sigaction` field, but because the distinction was
not made, the field was not checked.

The latest ctest version can check volatile pointers, so a couple of skipped
tests are now tested using this feature.

Moved inotify_rm_watch out of the generic notbsd target and into specific linux and android targets because the second argument has a different type in android and linux.

Since these are defined in C as macros, they must be reimplemented in
libc as Rust functions.  They're hard to get exactly right, and they
vary from platform to platform.  The test builds custom C code that uses
the real macros, and compares its output to the Rust versions' output
for various inputs.

Skip the CMSG_NXTHDR test on sparc64 linux because it hits a Bus Error.

Issue #1239

Skip the entire cmsg test program on s390x because it dumps core
seemingly before the kernel finishes booting.

Issue #1240

Per the mailing list[1], sys/ioctl_compat.h has been removed.

1: http://lists.dragonflybsd.org/pipermail/commits/2018-April/672079.html

This reverts commit 0581f926.

This reverts commit 0dd7f2d1.

separate for gnu and msvc


scope resolve c_int

these types are not allowed, and more scope resolution


use size_t

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

Bumps [ctest](https://github.com/alexcrichton/ctest) from 0.2.7 to 0.2.8.
- [Release notes](https://github.com/alexcrichton/ctest/releases)
- [Commits](https://github.com/alexcrichton/ctest/commits

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [ctest](https://github.com/alexcrichton/ctest) from 0.2.6 to 0.2.7.
- [Release notes](https://github.com/alexcrichton/ctest/releases)
- [Commits](https://github.com/alexcrichton/ctest/commits/0.2.7

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

Signed-off-by: Gerd Zellweger <mail@gerdzellweger.com>

This commit prepares the `libc` crate to be included directly into the
standard library via crates.io. More details about this can be found on
rust-lang/rust#56092, but the main idea is that this crate now depends
on core/compiler-builtins explicitly (but off-by-default).

The main caveat here is that this activates `no_core` when building as
part of libstd, which means that it needs to explicitly have an `iter`
and `option` module for the expansion of `for` loops to work.