Fix windows build.

src/log.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 451 matching lines @@
       int utf8_length = Min(str->length(), kUtf8BufferSize - utf8_pos_);
       String::WriteToFlat(str, utf8_buffer_ + utf8_pos_, 0, utf8_length);
       utf8_pos_ += utf8_length;
       return;
     }
     int uc16_length = Min(str->length(), kUc16BufferSize);
     String::WriteToFlat(str, uc16_buffer_, 0, uc16_length);
     for (int i = 0; i < uc16_length && utf8_pos_ < kUtf8BufferSize; ++i) {
       uc16 c = uc16_buffer_[i];
       if (c <= String::kMaxAsciiCharCodeU) {
-        utf8_buffer_[utf8_pos_++] = c;
+        utf8_buffer_[utf8_pos_++] = static_cast<char>(c);
       } else {
         int char_length = unibrow::Utf8::Length(c);
         if (utf8_pos_ + char_length > kUtf8BufferSize) break;
         unibrow::Utf8::Encode(utf8_buffer_ + utf8_pos_, c);
         utf8_pos_ += char_length;
       }
     }
   }
 
   void AppendBytes(const char* bytes, int size) {
@@ skipping 1507 matching lines @@
 void SamplerRegistry::RemoveActiveSampler(Sampler* sampler) {
   ASSERT(sampler->IsActive());
   ScopedLock lock(mutex_);
   ASSERT(active_samplers_ != NULL);
   bool removed = active_samplers_->RemoveElement(sampler);
   ASSERT(removed);
   USE(removed);
 }
 
 } }  // namespace v8::internal