[wasm] Lazy compilation for asm.js

src/wasm/wasm-module.h

Index: src/wasm/wasm-module.h
diff --git a/src/wasm/wasm-module.h b/src/wasm/wasm-module.h
index 67fff1d2007163d864a7d47936714460aec43cd6..384287e0b68ff2aef52c6f947652ad15e50d1a0f 100644
--- a/src/wasm/wasm-module.h
+++ b/src/wasm/wasm-module.h
@@ -271,11 +271,30 @@ struct V8_EXPORT_PRIVATE ModuleWireBytes {
 // minimal information about the globals, functions, and function tables.
 struct V8_EXPORT_PRIVATE ModuleEnv {
   ModuleEnv(const WasmModule* module, WasmInstance* instance)
-      : module(module), instance(instance) {}
+      : module(module), instance(instance) {
+    if (instance) {
+      function_tables = &instance->function_tables;
+      signature_tables = &instance->signature_tables;
+    }
+  }
 
   const WasmModule* module;
   WasmInstance* instance;
 
+  // TODO(clemensh): Find a better solution for this.
+  std::vector<Handle<FixedArray>>* function_tables = nullptr;
+  std::vector<Handle<FixedArray>>* signature_tables = nullptr;
+  bool used_indirect_tables = false;
+
+  Handle<FixedArray> GetFunctionTableObj(size_t index) {
+    used_indirect_tables = true;
+    return (*function_tables)[index];
+  }
+  Handle<FixedArray> GetSignatureTableObj(size_t index) {
+    used_indirect_tables = true;
+    return (*signature_tables)[index];
+  }
+
   bool IsValidGlobal(uint32_t index) const {
     return module && index < module->globals.size();
   }
@@ -443,6 +462,8 @@ V8_EXPORT_PRIVATE void AsyncCompileAndInstantiate(
     Isolate* isolate, Handle<JSPromise> promise, const ModuleWireBytes& bytes,
     MaybeHandle<JSReceiver> imports);
 
+Handle<Code> CompileLazy(Isolate* isolate);
+
 namespace testing {
 void ValidateInstancesChain(Isolate* isolate,
                             Handle<WasmModuleObject> module_obj,