sh: Allow multiple operands in wait builtin.

This is only part of the PR; the behaviour for unknown/invalid pids/jobs
remains unchanged (aborts the builtin with status 2).

PR:		176916
Submitted by:	Vadim Goncharov

bin/sh/jobs.c

@@ -95,6 +95,7 @@ static int ttyfd = -1;
 static void restartjob(struct job *);
 #endif
 static void freejob(struct job *);
+static int waitcmdloop(struct job *);
 static struct job *getjob(char *);
 pid_t getjobpgrp(char *);
 static pid_t dowait(int, struct job *);
@@ -459,15 +460,26 @@ int
 waitcmd(int argc __unused, char **argv __unused)
 {
 	struct job *job;
-	int status, retval;
-	struct job *jp;
+	int retval;
 
 	nextopt("");
-	if (*argptr != NULL) {
+	if (*argptr == NULL)
+		return (waitcmdloop(NULL));
+
+	do {
 		job = getjob(*argptr);
-	} else {
-		job = NULL;
-	}
+		retval = waitcmdloop(job);
+		argptr++;
+	} while (*argptr != NULL);
+
+	return (retval);
+}
+
+static int
+waitcmdloop(struct job *job)
+{
+	int status, retval;
+	struct job *jp;
 
 	/*
 	 * Loop until a process is terminated or stopped, or a SIGINT is

tools/regression/bin/sh/builtins/wait8.0

@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+exit 44 & p44=$!
+exit 45 & p45=$!
+exit 7 & p7=$!
+wait "$p44" "$p7" "$p45"
+[ "$?" = 45 ]