fuchsia: clean up module

There are type definitions that do not exist upstream. There are records
with wrong fields. There are records with wrong alignment. There are
incorrect pollyfils for macros.

This patch fixes most of it. But there's stuff I've missed.

Author: dybucc

src/fuchsia/aarch64.rs

@@ -1,10 +1,11 @@
 use crate::off_t;
 use crate::prelude::*;
 
+#[deprecated(
+    since = "0.2.187",
+    note = "This type doesn't exist. The Fuchsia SDK doesn't ship it."
+)]
 pub type __u64 = c_ulonglong;
-pub type wchar_t = u32;
-pub type nlink_t = c_ulong;
-pub type blksize_t = c_long;
 
 s! {
     pub struct stat {
@@ -15,20 +16,21 @@ s! {
         pub st_uid: crate::uid_t,
         pub st_gid: crate::gid_t,
         pub st_rdev: crate::dev_t,
-        __pad0: Padding<c_ulong>,
+        __pad: Padding<c_ulong>,
         pub st_size: off_t,
         pub st_blksize: crate::blksize_t,
-        __pad1: Padding<c_int>,
+        __pad2: Padding<c_int>,
         pub st_blocks: crate::blkcnt_t,
-        pub st_atime: crate::time_t,
-        pub st_atime_nsec: c_long,
-        pub st_mtime: crate::time_t,
-        pub st_mtime_nsec: c_long,
-        pub st_ctime: crate::time_t,
-        pub st_ctime_nsec: c_long,
-        __unused: Padding<[c_uint; 2]>,
+        pub st_atim: crate::timespec,
+        pub st_mtim: crate::timespec,
+        pub st_ctim: crate::timespec,
+        __unused1: Padding<[c_uint; 2]>,
     }
 
+    #[deprecated(
+        since = "0.2.187",
+        note = "This type doesn't exist. It's not part of the Fuchsia SDK."
+    )]
     pub struct stat64 {
         pub st_dev: crate::dev_t,
         pub st_ino: crate::ino_t,
@@ -51,6 +53,10 @@ s! {
         __unused: Padding<[c_uint; 2]>,
     }
 
+    #[deprecated(
+        since = "0.2.187",
+        note = "This type doesn't exist. It's not part of the Fuchsia SDK."
+    )]
     pub struct ipc_perm {
         pub __ipc_perm_key: crate::key_t,
         pub uid: crate::uid_t,
@@ -62,6 +68,25 @@ s! {
         __unused1: Padding<c_ulong>,
         __unused2: Padding<c_ulong>,
     }
+
+    // FIXME(i128): __reserved is meant to be an array of `long double`s. That
+    // requires native support for `i128`. This is currently missing.
+    pub struct mcontext_t {
+        pub fault_address: c_ulong,
+        pub regs: [c_ulong; 31],
+        pub sp: c_ulong,
+        pub pc: c_ulong,
+        pub pstate: c_ulong,
+        __reserved: Padding<[c_longlong; 256]>,
+    }
+
+    pub struct ucontext_t {
+        pub uc_flags: c_ulong,
+        pub uc_link: *mut crate::ucontext_t,
+        pub uc_stack: crate::stack_t,
+        pub uc_sigmask: crate::sigset_t,
+        pub uc_mcontext: crate::mcontext_t,
+    }
 }
 
 // From https://cs.opensource.google/fuchsia/fuchsia/+/main:zircon/third_party/ulib/musl/include/bits/signal.h;l=20-21;drc=0827b18ab9540c46f8037f407d17ea15a79e9ba7