Add a "fork" of musl as //fusl.
This is musl verbatim at d5f8394f6ea9549607567bd92de12a2446c15614.
See http://www.musl-libc.org/.
R=kulakowski@chromium.org
Review URL: https://codereview.chromium.org/1573973002 .
diff --git a/fusl/include/sys/wait.h b/fusl/include/sys/wait.h
new file mode 100644
index 0000000..50c5c70
--- /dev/null
+++ b/fusl/include/sys/wait.h
@@ -0,0 +1,59 @@
+#ifndef _SYS_WAIT_H
+#define _SYS_WAIT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <features.h>
+
+#define __NEED_pid_t
+#define __NEED_id_t
+#include <bits/alltypes.h>
+
+typedef enum {
+ P_ALL = 0,
+ P_PID = 1,
+ P_PGID = 2
+} idtype_t;
+
+pid_t wait (int *);
+pid_t waitpid (pid_t, int *, int );
+
+#if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
+ || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
+ || defined(_BSD_SOURCE)
+#include <signal.h>
+int waitid (idtype_t, id_t, siginfo_t *, int);
+#endif
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#include <sys/resource.h>
+pid_t wait3 (int *, int, struct rusage *);
+pid_t wait4 (pid_t, int *, int, struct rusage *);
+#endif
+
+#define WNOHANG 1
+#define WUNTRACED 2
+
+#define WSTOPPED 2
+#define WEXITED 4
+#define WCONTINUED 8
+#define WNOWAIT 0x1000000
+
+#define __WNOTHREAD 0x20000000
+#define __WALL 0x40000000
+#define __WCLONE 0x80000000
+
+#define WEXITSTATUS(s) (((s) & 0xff00) >> 8)
+#define WTERMSIG(s) ((s) & 0x7f)
+#define WSTOPSIG(s) WEXITSTATUS(s)
+#define WCOREDUMP(s) ((s) & 0x80)
+#define WIFEXITED(s) (!WTERMSIG(s))
+#define WIFSTOPPED(s) ((short)((((s)&0xffff)*0x10001)>>8) > 0x7f00)
+#define WIFSIGNALED(s) (((s)&0xffff)-1U < 0xffu)
+#define WIFCONTINUED(s) ((s) == 0xffff)
+
+#ifdef __cplusplus
+}
+#endif
+#endif
