Revert "Link to libgcc when statically linking musl"

This causes linker errors due to duplicated symbols. See https://github.com/rust-lang/rust/pull/52157

This reverts commit 920cfeac.

Add MODULE_INIT_ constants

These are flags required to implement the linux kernel loading mechanism.
Specifically finit_module.

These are flags required to implement the linux kernel loading mechanism.
Specifically finit_module.

Implement statfs for dragonfly, freebsd and openbsd

Openbsd fix

put in several fixes for OpenBSD (one fix per commit).
testsuite ran on OpenBSD 6.3-current (upcoming 6.4)

```
RUNNING ALL TESTS
PASSED 6474 tests
```

they doesn't exists on OpenBSD. put them under NetBSD specific tree.

Fix netbsd build with "stdbuild"

A bug was introduced in #930 which caused netbsd to not link to libm.

r? @alexcrichton

Fix a #[cfg] attribute

It looks like this was a mistake of #930 but should be easy to fix!

It looks like this was a mistake of #930 but should be easy to fix!

Link to libgcc when statically linking musl

On some architectures (e.g. aarch64) musl depends on some libgcc functions (`__addtf3`, `__multf3`, `__subtf3`) for `long double` arithmetic that it uses internally. Unfortunately we don't provide these functions in compiler-builtins, so we instead need to get them from libgcc.

Fixes:
https://github.com/rust-lang/rust/issues/46651
https://github.com/rust-lang-nursery/compiler-builtins/issues/201
https://github.com/rust-lang-nursery/compiler-builtins/issues/217

Bump ctest from `482c7f0` to `5c53723`

Bumps [ctest](https://github.com/alexcrichton/ctest) from `482c7f0` to `5c53723`.
<details>
<summary>Commits</summary>

- [`5c53723`](https://github.com/alexcrichton/ctest/commit/5c537236d150da311d67b8ccf4c3c49987b92c8d) Update libc dep
- See full diff in [compare view](https://github.com/alexcrichton/ctest/compare/482c7f0643942174a802d89ad7d460e89b576ed3...5c537236d150da311d67b8ccf4c3c49987b92c8d)
</details>
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Bumps [ctest](https://github.com/alexcrichton/ctest) from `482c7f0` to `5c53723`.
- [Release notes](https://github.com/alexcrichton/ctest/releases)
- [Commits](https://github.com/alexcrichton/ctest/compare/482c7f0643942174a802d89ad7d460e89b576ed3...5c537236d150da311d67b8ccf4c3c49987b92c8d

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Add if_packet.h headers

Some structs for implementing af_packet(7)

Some structs for implementing af_packet(7)

Add linux musl powerpc (32-bit) support

This change adds support for musl on 32-bit powerpc.  Most of the general constants in src/unix/notbsd/linux/musl/b32/mod.rs were different from those of the powerpc port, so I moved them over to the individual architecture-specific submodules.  The same with the ipc_perm structure.

Add ENOATTR for Android

PR based on https://github.com/rust-lang/libc/pull/594

It's defined in Android sysroot so it should work without test workaround (CI should catch it otherwise?).

Remove `#![custom_attribute]`

No longer needed by the looks of it!

No longer needed by the looks of it!

added badges

added Documentation, Latest Version, License badges similar to rand crate. https://crates.io/crates/rand

Re-add aarch64 stuff removed by previous PR

Previous PR #1023 has removed stuff from mod.rs and added it to some submodules, but
missed the aarch64 submodule.

This caused a build failure for rust on aarch64, see https://github.com/rust-lang/rust/pull/51864.

This copies the stuff that that commit added to the x86_64.rs submodule
and puts it into aarch64.rs.

It's been tested in the rust-lang/rust PR above: https://travis-ci.org/rust-lang/rust/builds/398750336

Previous commit

dcff1547
"libc: changes to ppc64le musl branch to support building of rust on Alpine"

has removed stuff from mod.rs and added it to some submodules, but
missed the aarch64 submodule.

This copies the stuff that that commit added to the x86_64.rs submodule
and puts it into aarch64.rs.

added Documentation, Latest Version, License badges similar to rand crate. https://crates.io/crates/rand