Fix off-by-one issue in clustered snapshot implementation and api impl

runtime/vm/dart_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "lib/stacktrace.h"
@@ skipping 598 matching lines @@
   }
   return false;
 }
 
 
 bool Api::GetNativeReceiver(NativeArguments* arguments, intptr_t* value) {
   NoSafepointScope no_safepoint_scope;
   RawObject* raw_obj = arguments->NativeArg0();
   if (raw_obj->IsHeapObject()) {
     intptr_t cid = raw_obj->GetClassId();
-    if (cid > kNumPredefinedCids) {
+    if (cid >= kNumPredefinedCids) {
       ASSERT(Instance::Cast(Object::Handle(raw_obj)).IsValidNativeIndex(0));
       RawTypedData* native_fields = *reinterpret_cast<RawTypedData**>(
           RawObject::ToAddr(raw_obj) + sizeof(RawObject));
       if (native_fields == TypedData::null()) {
         *value = 0;
       } else {
         *value = *bit_cast<intptr_t*, uint8_t*>(native_fields->ptr()->data());
       }
       return true;
     }
@@ skipping 64 matching lines @@
 
 
 bool Api::GetNativeFieldsOfArgument(NativeArguments* arguments,
                                     int arg_index,
                                     int num_fields,
                                     intptr_t* field_values) {
   NoSafepointScope no_safepoint_scope;
   RawObject* raw_obj = arguments->NativeArgAt(arg_index);
   if (raw_obj->IsHeapObject()) {
     intptr_t cid = raw_obj->GetClassId();
-    if (cid > kNumPredefinedCids) {
+    if (cid >= kNumPredefinedCids) {
       RawTypedData* native_fields = *reinterpret_cast<RawTypedData**>(
           RawObject::ToAddr(raw_obj) + sizeof(RawObject));
       if (native_fields == TypedData::null()) {
         memset(field_values, 0, (num_fields * sizeof(field_values[0])));
       } else if (num_fields == Smi::Value(native_fields->ptr()->length_)) {
         intptr_t* native_values =
             bit_cast<intptr_t*, uint8_t*>(native_fields->ptr()->data());
         memmove(field_values,
                 native_values,
                 (num_fields * sizeof(field_values[0])));
@@ skipping 5906 matching lines @@
 
 DART_EXPORT bool Dart_IsPrecompiledRuntime() {
 #if defined(DART_PRECOMPILED_RUNTIME)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace dart