Split out libplatform into a separate libary

src/api.cc

 // Copyright 2012 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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 4913 matching lines @@
   if (obj->IsUndefined()) return NULL;
   i::Object* foreign = i::JSObject::cast(obj)->GetInternalField(0);
   return i::Foreign::cast(foreign)->foreign_address();
 }
 
 
 // --- E n v i r o n m e n t ---
 
 
 void v8::V8::InitializePlatform(Platform* platform) {
-#ifdef V8_USE_DEFAULT_PLATFORM
-  FATAL("Can't override v8::Platform when using default implementation");
-#else
   i::V8::InitializePlatform(platform);
-#endif
 }
 
 
 void v8::V8::ShutdownPlatform() {
-#ifdef V8_USE_DEFAULT_PLATFORM
-  FATAL("Can't override v8::Platform when using default implementation");
-#else
   i::V8::ShutdownPlatform();
-#endif
 }
 
 
 bool v8::V8::Initialize() {
   i::Isolate* isolate = i::Isolate::UncheckedCurrent();
   if (isolate != NULL && isolate->IsInitialized()) {
     return true;
   }
   return InitializeHelper(isolate);
 }
@@ skipping 2668 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal