feat: O_EXEC/O_SEARCH for apple platforms

Author: SteveLauC

libc-test/semver/apple.txt

@@ -1035,11 +1035,13 @@ OXTABS
 O_ASYNC
 O_DSYNC
 O_EVTONLY
+O_EXEC
 O_EXLOCK
 O_FSYNC
 O_NDELAY
 O_NOCTTY
 O_NOFOLLOW_ANY
+O_SEARCH
 O_SHLOCK
 O_SYMLINK
 O_SYNC

src/unix/bsd/apple/mod.rs

@@ -3252,6 +3252,8 @@ pub const O_SYMLINK: ::c_int = 0x00200000;
 pub const O_DSYNC: ::c_int = 0x00400000;
 pub const O_CLOEXEC: ::c_int = 0x01000000;
 pub const O_NOFOLLOW_ANY: ::c_int = 0x20000000;
+pub const O_EXEC: ::c_int = 0x40000000;
+pub const O_SEARCH: ::c_int = O_EXEC | O_DIRECTORY;
 pub const S_IFIFO: mode_t = 4096;
 pub const S_IFCHR: mode_t = 8192;
 pub const S_IFBLK: mode_t = 24576;