Auto merge of rust-lang#2652 - Mek101:master, r=Amanieu

Fix linux ioctl BLKSSZGET and BLKPBSZGET constants types.

The BLKSSZGET and BLKPBSZGET constants weren't arch dependent as they should have.

Auto merge of rust-lang#2636 - skrap:master, r=Amanieu

uclibc: fix O_TMPFILE value, hide some unused fields to fix libc-test

This was a bit of a yak-shave.

First, O_TMPFILE was wrong because 020000000 is decimal, not octal.  🤦   This was, of course, causing all sorts of things to be horrible.

That led me to switch to a newer toolchain which actually defined O_TMPFILE, so that the libc tests pass on `armv7-unknown-linux-uclibceabihf`.

That revealed that certain field names had changed since the last time I ran the libc tests on this architecture, which revealed that some struct fields (e.g. `__unused`) were being marked as `pub` where all other architectures left them as private.

So, this patch might seem somewhat sprawling, but without all of these changes it's not possible to run libc-test!

To test:
* get https://toolchains.bootlin.com/downloads/releases/toolchains/armv7-eabihf/tarballs/armv7-eabihf--uclibc--bleeding-edge-2021.11-1.tar.bz2
* unpack somewhere, and call that `$TOOLCHAIN`
```
cd libc-test

PATH=$TOOLCHAIN/bin:$PATH \
  CC_armv7_unknown_linux_uclibc=armv7-buildroot-linux-uclibc-gcc \
  CARGO_TARGET_ARMV7_UNKNOWN_LINUX_UCLIBCEABIHF_LINKER=armv7-buildroot-linux-uclibc-gcc \
  CARGO_TARGET_ARMV7_UNKNOWN_LINUX_UCLIBCEABIHF_RUNNER="qemu-arm -L $TOOLCHAIN/arm-buildroot-linux-uclibcgnueabihf/sysroot/" \
  cargo +nightly test --target armv7-unknown-linux-uclibceabihf -Zbuild-std=core,std
```

Auto merge of rust-lang#2590 - GuillaumeGomez:private-fields, r=Amanieu

Make some freebsd private struct fields public and upgrade crate version to 0.2.112

Otherwise we can't use the structs at all...

Auto merge of rust-lang#2588 - GuillaumeGomez:upgrade, r=Amanieu

Upgrade crate version to 0.2.111

r? `@Amanieu`

Auto merge of rust-lang#2584 - GuillaumeGomez:upgrade, r=Amanieu

Upgrade crate version to 0.2.110

Auto merge of rust-lang#2578 - GuillaumeGomez:upgrade, r=Amanieu

Upgrade crate version to 0.2.109

r? `@Amanieu`

Auto merge of rust-lang#2541 - GuillaumeGomez:upgrade, r=JohnTitor

Upgrade crate version to 0.2.108

Auto merge of rust-lang#2515 - workingjubilee:bump-ver, r=JohnTitor

Bump libc to 0.2.107

Primarily so as to fix building for aarch64-unknown-linux-musl,
as implemented in commit fd331f6

This may help resolve rust-lang/rust#90044
I do not have release privileges for libc, so if anyone would be so kind as to tag it and publish to crates.io, that would be lovely.

Auto merge of rust-lang#2469 - GuillaumeGomez:upgrade-version, r=John…

…Titor

Upgrade crate version to 0.2.105

Upgrading the version so I can use the newly added freebsd items. :)