[newlib-cygwin] Cygwin: sys/wait.h: Add _wait prototype to avoid compiler warning

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=7630c77026da1c98a0c77f50ad3fbd4589a7a260

commit 7630c77026da1c98a0c77f50ad3fbd4589a7a260
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Tue Sep 3 12:45:55 2019 +0200

    Cygwin: sys/wait.h: Add _wait prototype to avoid compiler warning
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/include/sys/wait.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/winsup/cygwin/include/sys/wait.h b/winsup/cygwin/include/sys/wait.h
index 97e5d99..1ed1f5a 100644
--- a/winsup/cygwin/include/sys/wait.h
+++ b/winsup/cygwin/include/sys/wait.h
@@ -22,6 +22,10 @@ pid_t waitpid (pid_t __pid, int *__status, int __options);
 pid_t wait3 (int *__status, int __options, struct rusage *__rusage);
 pid_t wait4 (pid_t __pid, int *__status, int __options, struct rusage *__rusage);
 
+#ifdef _COMPILING_NEWLIB
+pid_t _wait (int *);
+#endif
+
 #ifdef __cplusplus
 }
 #endif