[wasm] More extensive indirect dispatch signature mismatch tests.

src/wasm/signature-map.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/wasm/signature-map.h"
 
 namespace v8 {
 namespace internal {
 namespace wasm {
 
+SignatureMap::SignatureMap() : mutex_(new base::Mutex()) {}
+
 uint32_t SignatureMap::FindOrInsert(FunctionSig* sig) {
+  base::LockGuard<base::Mutex> guard(mutex_.get());
   auto pos = map_.find(sig);
   if (pos != map_.end()) {
     return pos->second;
   } else {
     uint32_t index = next_++;
     map_[sig] = index;
     return index;
   }
 }
 
 int32_t SignatureMap::Find(FunctionSig* sig) const {
+  base::LockGuard<base::Mutex> guard(mutex_.get());
   auto pos = map_.find(sig);
   if (pos != map_.end()) {
     return static_cast<int32_t>(pos->second);
   } else {
     return -1;
   }
 }
 
 bool SignatureMap::CompareFunctionSigs::operator()(FunctionSig* a,
                                                    FunctionSig* b) const {
   if (a == b) return false;
   if (a->return_count() < b->return_count()) return true;
   if (a->return_count() > b->return_count()) return false;
   if (a->parameter_count() < b->parameter_count()) return true;
   if (a->parameter_count() > b->parameter_count()) return false;
   for (size_t r = 0; r < a->return_count(); r++) {
     if (a->GetReturn(r) < b->GetReturn(r)) return true;
     if (a->GetReturn(r) > b->GetReturn(r)) return false;
   }
   for (size_t p = 0; p < a->parameter_count(); p++) {
     if (a->GetParam(p) < b->GetParam(p)) return true;
     if (a->GetParam(p) > b->GetParam(p)) return false;
   }
   return false;
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8