[wasm] Support recompilation if deserialization fails.

src/snapshot/code-serializer.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/snapshot/code-serializer.h"
 
 #include <memory>
 
 #include "src/code-stubs.h"
 #include "src/log.h"
@@ skipping 322 matching lines @@
   CopyBytes(data_ + padded_payload_offset, payload->begin(),
             static_cast<size_t>(payload->length()));
 
   Checksum checksum(DataWithoutHeader());
   SetHeaderValue(kChecksum1Offset, checksum.a());
   SetHeaderValue(kChecksum2Offset, checksum.b());
 }
 
 SerializedCodeData::SanityCheckResult SerializedCodeData::SanityCheck(
     Isolate* isolate, uint32_t expected_source_hash) const {
+  if (this->size_ < kHeaderSize) return INVALID_HEADER;
   uint32_t magic_number = GetMagicNumber();
   if (magic_number != ComputeMagicNumber(isolate)) return MAGIC_NUMBER_MISMATCH;
   uint32_t version_hash = GetHeaderValue(kVersionHashOffset);
   uint32_t source_hash = GetHeaderValue(kSourceHashOffset);
   uint32_t cpu_features = GetHeaderValue(kCpuFeaturesOffset);
   uint32_t flags_hash = GetHeaderValue(kFlagHashOffset);
   uint32_t c1 = GetHeaderValue(kChecksum1Offset);
   uint32_t c2 = GetHeaderValue(kChecksum2Offset);
   if (version_hash != Version::Hash()) return VERSION_MISMATCH;
   if (source_hash != expected_source_hash) return SOURCE_MISMATCH;
@@ skipping 56 matching lines @@
   *rejection_result = scd.SanityCheck(isolate, expected_source_hash);
   if (*rejection_result != CHECK_SUCCESS) {
     cached_data->Reject();
     return SerializedCodeData(nullptr, 0);
   }
   return scd;
 }
 
 }  // namespace internal
 }  // namespace v8