Add some missing files.

src/lib9/lnrand.c

@@ -0,0 +1,18 @@
+#include	<u.h>
+#include	<libc.h>
+
+#define	MASK	0x7fffffffL
+
+long
+lnrand(long n)
+{
+	long slop, v;
+
+	if(n < 0)
+		return n;
+	slop = MASK % n;
+	do
+		v = lrand();
+	while(v <= slop);
+	return v % n;
+}

src/lib9/lrand.c

@@ -0,0 +1,8 @@
+#include	<u.h>
+#include	<libc.h>
+
+long
+lrand(void)
+{
+	return ((rand()<<16)^rand()) & 0x7FFFFFFF;
+}

src/lib9/opentemp.c

@@ -0,0 +1,9 @@
+#include <u.h>
+#include <libc.h>
+
+int
+opentemp(char *template)
+{
+	return mkstemp(template);
+}
+