Add a hack to <stdlib.h> until we can fix libvpx.

libvpx should probably change its assembler to refer to lrand48 directly,
because that will work on old and new versions of Android. This keeps things
building until that happens.

Bug: 15598056
Change-Id: I4a1f59e710a083b9f9a707ceeb9ca0a28141a954

libc/include/stdlib.h

@@ -106,6 +106,12 @@ extern void arc4random_addrandom(unsigned char *, int);
 
 #define RAND_MAX 0x7fffffff
 
+/* Work around x86 libvpx build breakage caused by postproc_x86.c. */
+#if defined(__i386__) && defined(rand)
+#undef rand
+#define __rand lrand48
+#endif
+
 int rand(void);
 int rand_r(unsigned int*);
 void srand(unsigned int);