[wasm] Lazy compilation for asm.js

src/runtime/runtime-wasm.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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/assembler.h"
 #include "src/compiler/wasm-compiler.h"
 #include "src/conversions.h"
@@ skipping 190 matching lines @@
   DCHECK_NULL(isolate->context());
   isolate->set_context(GetWasmContextOnStackTop(isolate));
 
   // Check if this is a real stack overflow.
   StackLimitCheck check(isolate);
   if (check.JsHasOverflowed()) return isolate->StackOverflow();
 
   return isolate->stack_guard()->HandleInterrupts();
 }
 
+RUNTIME_FUNCTION(Runtime_WasmCompileLazy) {
+  DCHECK(args.length() == 0);
+  HandleScope scope(isolate);
+
+  return *wasm::CompileLazy(isolate);
+}
+
 }  // namespace internal
 }  // namespace v8