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Closes #651 .

Add alias for MAP_ANONYMOUS to Apple targets.

Closes #1060 .

Closes #651 .

Closes #1060 .

No longer needed and this is done via other means in upstream rustc

Prepare for being included via crates.io into std

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.

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.

Add SGX C types

cc @jethrogb

core::ffi::c_void is available since rustc 1.30

Add missing condition for musl mips64

unix::uclibc::mips has both support for mips and mips64, but it's
currently only imported for mips.

unix::uclibc::mips has both support for mips and mips64, but it's
currently only imported for mips.

Use Reqwest backend for Appveyor, not Hyper which is deprecated

Since https://github.com/rust-lang-nursery/rustup.rs/pull/1222 Appveyor builds have been complaining, so should stop asking for the Hyper backend

Factor out platforms for which libc is empty

This change shouldn't change any functionality. It just separates the platforms for which `libc` is currently empty (only `wasm32-unknown-unknown`), from those for which it isn't. This is a non-functional change.

Formatting and shellcheck

Add chflags(2) and friends

Use OR in the license field

According to [The Manifest Format](https://doc.rust-lang.org/cargo/reference/manifest.html):
>Multiple licenses can be separated with a `/`, although that usage is deprecated.  Instead, use a license expression with AND and OR operators to get more explicit semantics.

the f macro is unused in some targets

Add support for SIGSYS in signalfd

Android's NDK typedefs __u64 as unsigned long long.

Linux 4.18 added support for SIGSYS info in signalfd. Add the new
fields to signalfd_siginfo.

While the kernel has support for these new fields now, no libc has
shipped a release with the new signalfd fields.

NetBSD: these extattr functions are not in libutil, but libc

 - extattr_namespace_to_string()
 - extattr_string_to_namespace()

Add F_RDLCK/F_WRLCK/F_UNLCK to several platforms

These are used by the flock wrapper in rustc_data_structures. The constants were already present in x86_64-linux-gnu and BSD (since 4928bd98).

Currently the `flock` wrapper in `rustc_data_structures` does not work on several 32-bit musl targets, because they expect the `LARGEFILE64` version of the `F_SETLK`/`F_SETLKW` constants. This PR is a prerequisite to converting that code to use the `libc` types and constants, instead of (inaccurately) duplicating them, since `libc` already provides architecture-specific definitions of the relevant constants.

 - extattr_namespace_to_string()
 - extattr_string_to_namespace()

These are used by the flock wrapper in rustc_data_structures. The
constants were already present in x86_64-linux-gnu and BSD (since
4928bd98).

NetBSD: fix extattr_set_* return types

On FreeBSD and Dragonfly, don't unnecessarily link to libutil

Also, alphabetize this section, since I'm merging two sections anyway.

Fixes #1113

NetBSD: fix pthread types on arm and powerpc

Bump ctest from 0.2.4 to 0.2.6