Update NativeInteger_rfill.c to respect PER constraints

`NativeInteger_rfill.c` was sometimes ignoring the PER constrains. @lbm98 added a check which was also present in BIT_STRING_rfill.c to respect them.

skeletons/NativeInteger_rfill.c

@@ -63,8 +63,10 @@ NativeInteger_random_fill(const asn_TYPE_descriptor_t *td, void **sptr,
                 0, sizeof(variants) / sizeof(variants[0]) - 1)];
         }
 
-        if(!constraints) constraints = &td->encoding_constraints;
 #if !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT)
+        if(!constraints || !constraints->per_constraints) 
+            constraints = &td->encoding_constraints;
+
         const asn_per_constraints_t *ct;
 
         ct = constraints ? constraints->per_constraints : 0;
@@ -74,6 +76,8 @@ NativeInteger_random_fill(const asn_TYPE_descriptor_t *td, void **sptr,
                                            ct->value.upper_bound);
             }
         }
+#else
+      if(!constraints) constraints = &td->encoding_constraints;
 #endif  /* !defined(ASN_DISABLE_UPER_SUPPORT) || !defined(ASN_DISABLE_APER_SUPPORT) */
     }