Add POSIX lcong48.

Change-Id: I821046816661d77275cb02c8c99d526bb41afb9c
diff --git a/libc/include/stdlib.h b/libc/include/stdlib.h
index b97eaf9..3053e85 100644
--- a/libc/include/stdlib.h
+++ b/libc/include/stdlib.h
@@ -103,15 +103,6 @@
 
 extern void qsort(void *, size_t, size_t, int (*)(const void *, const void *));
 
-extern long jrand48(unsigned short *);
-extern long mrand48(void);
-extern long nrand48(unsigned short *);
-extern long lrand48(void);
-extern unsigned short *seed48(unsigned short*);
-extern double erand48(unsigned short xsubi[3]);
-extern double drand48(void);
-extern void srand48(long);
-
 uint32_t arc4random(void);
 uint32_t arc4random_uniform(uint32_t);
 void arc4random_buf(void*, size_t);
@@ -122,6 +113,16 @@
 int rand_r(unsigned int*);
 void srand(unsigned int);
 
+double drand48(void);
+double erand48(unsigned short[3]);
+long jrand48(unsigned short[3]);
+void lcong48(unsigned short[7]);
+long lrand48(void);
+long mrand48(void);
+long nrand48(unsigned short[3]);
+unsigned short* seed48(unsigned short[3]);
+void srand48(long);
+
 char* initstate(unsigned int, char*, size_t);
 long random(void);
 char* setstate(char*);