Fix {aarch64,arm}-android targets' CI

Android: Add VMADDR_ constants.

pthread_getattr_np is not present on illumos

Fix bootstrap on redox

Avoid attempting to enable the static_nobundle feature twice, which
results in rustc error E0636.

Add more constants for Linux like OS

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Add SYS_pidfd_open and SYS_clone3

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

There was a missing period and the word "features" instead of "feature" in the section about `const extern fn`s.

In the `no-std` section of the README, there was a typo: "disable this feature remove the dependency". The word "to" was added in this commit to create "disable this feature to remove this dependency".

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Add struct ip_mreqn to more Linux targets

Fix type definition for c_char on sparc-unknown-linux-gnu

Android: Add vsock constants and struct.

Add UIO_MAXIOV constant to uclibc

On sparc-unknown-linux-gnu, char is signed, not unsigned.

Support was previously added to gnu x86_64 and all musl targets but
others were not included because of a roundtrip issue [1].

This commit adds support for the ip_mreqn struct on all Linux GNU
targets which did not have the roundtrip issue.

[1]: https://github.com/rust-lang/libc/issues/1558



Signed-off-by: Bartel Sielski <bartel.sielski@gmail.com>

Move the link line for `libdl` up to `src/unix/mod.rs`, making it easier
to see all the libraries `libc` links to.

This also makes `libdl` respect `target-feature=+crt-static`.

The two library blocks that specify `#[link(name = "util")]` do not
actually reference any functions in `libutil`; the functions that do use
`libutil` don't have any reference to it. And having two library blocks
specify it results in two separate inclusions of `-lutil` on the linker
command line. Move the link lines up to `src/unix/mod.rs`, making it
easier to see all the libraries `libc` links to.

This also makes `libutil` respect `target-feature=+crt-static`.