Add the ability to defer the initialization of the SyzyAsan crash reporter.

syzygy/agent/asan/rtl_impl.cc

 // Copyright 2012 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 241 matching lines @@
     ret
   }
 }
 #endif  // !defined _WIN64
 
 int asan_CrashForException(EXCEPTION_POINTERS* exception) {
   DCHECK_NE(static_cast<EXCEPTION_POINTERS*>(nullptr), exception);
   return agent::asan::AsanRuntime::CrashForException(exception);
 }
 
+void WINAPI asan_InitializeCrashHandler() {
+  asan_runtime->InitializeCrashReporter();
+}
+
 }  // extern "C"