Add a "fork" of musl as //fusl.

fusl/include/alltypes.h.in

+TYPEDEF unsigned _Addr size_t;
+TYPEDEF unsigned _Addr uintptr_t;
+TYPEDEF _Addr ptrdiff_t;
+TYPEDEF _Addr ssize_t;
+TYPEDEF _Addr intptr_t;
+TYPEDEF _Addr regoff_t;
+TYPEDEF _Reg register_t;
+
+TYPEDEF signed char     int8_t;
+TYPEDEF short           int16_t;
+TYPEDEF int             int32_t;
+TYPEDEF _Int64          int64_t;
+TYPEDEF _Int64          intmax_t;
+TYPEDEF unsigned char   uint8_t;
+TYPEDEF unsigned short  uint16_t;
+TYPEDEF unsigned int    uint32_t;
+TYPEDEF unsigned _Int64 uint64_t;
+TYPEDEF unsigned _Int64 u_int64_t;
+TYPEDEF unsigned _Int64 uintmax_t;
+
+TYPEDEF unsigned mode_t;
+TYPEDEF unsigned _Reg nlink_t;
+TYPEDEF _Int64 off_t;
+TYPEDEF unsigned _Int64 ino_t;
+TYPEDEF unsigned _Int64 dev_t;
+TYPEDEF long blksize_t;
+TYPEDEF _Int64 blkcnt_t;
+TYPEDEF unsigned _Int64 fsblkcnt_t;
+TYPEDEF unsigned _Int64 fsfilcnt_t;
+
+TYPEDEF unsigned wint_t;
+TYPEDEF unsigned long wctype_t;
+
+TYPEDEF void * timer_t;
+TYPEDEF int clockid_t;
+TYPEDEF long clock_t;
+STRUCT timeval { time_t tv_sec; suseconds_t tv_usec; };
+STRUCT timespec { time_t tv_sec; long tv_nsec; };
+
+TYPEDEF int pid_t;
+TYPEDEF unsigned id_t;
+TYPEDEF unsigned uid_t;
+TYPEDEF unsigned gid_t;
+TYPEDEF int key_t;
+TYPEDEF unsigned useconds_t;
+
+#ifdef __cplusplus
+TYPEDEF unsigned long pthread_t;
+#else
+TYPEDEF struct __pthread * pthread_t;
+#endif
+TYPEDEF int pthread_once_t;
+TYPEDEF unsigned pthread_key_t;
+TYPEDEF int pthread_spinlock_t;
+TYPEDEF struct { unsigned __attr; } pthread_mutexattr_t;
+TYPEDEF struct { unsigned __attr; } pthread_condattr_t;
+TYPEDEF struct { unsigned __attr; } pthread_barrierattr_t;
+TYPEDEF struct { unsigned __attr[2]; } pthread_rwlockattr_t;
+
+TYPEDEF struct _IO_FILE FILE;
+
+TYPEDEF struct __mbstate_t { unsigned __opaque1, __opaque2; } mbstate_t;
+
+TYPEDEF struct __locale_struct * locale_t;
+
+TYPEDEF struct __sigset_t { unsigned long __bits[128/sizeof(long)]; } sigset_t;
+
+STRUCT iovec { void *iov_base; size_t iov_len; };
+
+TYPEDEF unsigned socklen_t;
+TYPEDEF unsigned short sa_family_t;
+
+#undef _Addr
+#undef _Int64
+#undef _Reg