Auto merge of #2636 - skrap:master, r=Amanieu0.2.113

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.  :facepalm:   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
```

2 files changed, 20 insertions, 20 deletions

diff --git a/src/unix/linux_like/linux/uclibc/arm/mod.rs b/src/unix/linux_like/linux/uclibc/arm/mod.rs
index dc84b0c054..c1008a48f6 100644
--- a/src/unix/linux_like/linux/uclibc/arm/mod.rs
+++ b/src/unix/linux_like/linux/uclibc/arm/mod.rs
@@ -44,14 +44,14 @@ s! {
 
     pub struct stat {
         pub st_dev: ::c_ulonglong,
-        pub __pad1: ::c_ushort,
+        __pad1: ::c_ushort,
         pub st_ino: ::ino_t,
         pub st_mode: ::mode_t,
         pub st_nlink: ::nlink_t,
         pub st_uid: ::uid_t,
         pub st_gid: ::gid_t,
         pub st_rdev: ::c_ulonglong,
-        pub __pad2: ::c_ushort,
+        __pad2: ::c_ushort,
         pub st_size: ::off_t,
         pub st_blksize: ::blksize_t,
         pub st_blocks: ::blkcnt_t,
@@ -61,8 +61,8 @@ s! {
         pub st_mtime_nsec: ::c_long,
         pub st_ctime: ::time_t,
         pub st_ctime_nsec: ::c_long,
-        pub __unused4: ::c_ulong,
-        pub __unused5: ::c_ulong,
+        __unused4: ::c_ulong,
+        __unused5: ::c_ulong,
     }
 
     pub struct stat64
@@ -202,44 +202,44 @@ s! {
         pub cuid: ::uid_t,
         pub cgid: ::gid_t,
         pub mode: ::c_ushort,
-        pub __pad1: ::c_ushort,
+        __pad1: ::c_ushort,
         pub __seq: ::c_ushort,
-        pub __pad2: ::c_ushort,
-        pub __unused1: ::c_ulong,
-        pub __unused2: ::c_ulong,
+        __pad2: ::c_ushort,
+        __unused1: ::c_ulong,
+        __unused2: ::c_ulong,
     }
 
     pub struct msqid_ds {
         pub msg_perm: ::ipc_perm,
         pub msg_stime: ::time_t,
-        pub __unused1: ::c_ulong,
+        __unused1: ::c_ulong,
         pub msg_rtime: ::time_t,
-        pub __unused2: ::c_ulong,
+        __unused2: ::c_ulong,
         pub msg_ctime: ::time_t,
-        pub __unused3: ::c_ulong,
-        pub __msg_cbytes: ::c_ulong,
+        __unused3: ::c_ulong,
+        __msg_cbytes: ::c_ulong,
         pub msg_qnum: ::msgqnum_t,
         pub msg_qbytes: ::msglen_t,
         pub msg_lspid: ::pid_t,
         pub msg_lrpid: ::pid_t,
-        pub __unused4: ::c_ulong,
-        pub __unused5: ::c_ulong,
+        __unused4: ::c_ulong,
+        __unused5: ::c_ulong,
     }
 
     pub struct shmid_ds {
         pub shm_perm: ::ipc_perm,
         pub shm_segsz: ::size_t,
         pub shm_atime: ::time_t,
-        pub __unused1: ::c_ulong,
+        __unused1: ::c_ulong,
         pub shm_dtime: ::time_t,
-        pub __unused2: ::c_ulong,
+        __unused2: ::c_ulong,
         pub shm_ctime: ::time_t,
-        pub __unused3: ::c_ulong,
+        __unused3: ::c_ulong,
         pub shm_cpid: ::pid_t,
         pub shm_lpid: ::pid_t,
         pub shm_nattch: ::shmatt_t,
-        pub __unused4: ::c_ulong,
-        pub __unused5: ::c_ulong,
+        __unused4: ::c_ulong,
+        __unused5: ::c_ulong,
     }
 }
 
diff --git a/src/unix/linux_like/linux/uclibc/mod.rs b/src/unix/linux_like/linux/uclibc/mod.rs
index e25a6bfb48..8f23826f29 100644
--- a/src/unix/linux_like/linux/uclibc/mod.rs
+++ b/src/unix/linux_like/linux/uclibc/mod.rs
@@ -303,7 +303,7 @@ pub const MAP_HUGE_16GB: ::c_int = 34 << MAP_HUGE_SHIFT;
 pub const MINSIGSTKSZ: ::c_int = 2048;
 pub const MSG_COPY: ::c_int = 040000;
 pub const NI_MAXHOST: ::socklen_t = 1025;
-pub const O_TMPFILE: ::c_int = 020000000 | O_DIRECTORY;
+pub const O_TMPFILE: ::c_int = 0o20000000 | O_DIRECTORY;
 pub const PACKET_MR_UNICAST: ::c_int = 3;
 pub const PF_NFC: ::c_int = 39;
 pub const PF_VSOCK: ::c_int = 40;