Use a securely seeded global PRNG for the VM.

It's not 2005 anymore.

src/lj_trace.c

@@ -30,6 +30,7 @@
 #include "lj_vm.h"
 #include "lj_vmevent.h"
 #include "lj_target.h"
+#include "lj_prng.h"
 
 /* -- Error handling ------------------------------------------------------ */
 
@@ -384,7 +385,7 @@ static void penalty_pc(jit_State *J, GCproto *pt, BCIns *pc, TraceError e)
     if (mref(J->penalty[i].pc, const BCIns) == pc) {  /* Cache slot found? */
       /* First try to bump its hotcount several times. */
       val = ((uint32_t)J->penalty[i].val << 1) +
-	    LJ_PRNG_BITS(J, PENALTY_RNDBITS);
+	    (lj_prng_u64(&J2G(J)->prng) & ((1u<<PENALTY_RNDBITS)-1));
       if (val > PENALTY_MAX) {
 	blacklist_pc(pt, pc);  /* Blacklist it, if that didn't help. */
 	return;