FFI: Fix recording of userdata conversions.

src/lj_crecord.c

@@ -365,7 +365,7 @@ static TRef crec_ct_tv(jit_State *J, CType *d, TRef dp, TRef sp, TValue *sval)
   } else if (tref_isnil(sp)) {
     sp = lj_ir_kptr(J, NULL);
   } else if (tref_isudata(sp)) {
-    sp = emitir(IRT(IR_ADD, IRT_P32), sp, lj_ir_kint(J, sizeof(GCcdata)));
+    sp = emitir(IRT(IR_ADD, IRT_P32), sp, lj_ir_kint(J, sizeof(GCudata)));
   } else if (tref_isstr(sp)) {
     if (ctype_isenum(d->info)) {  /* Match string against enum constant. */
       GCstr *str = strV(sval);