[wasm] Remove {WasmExportedFunction::GetWasmCode}

With lazy compilation, not every exported function has code assiciated
with it. {WasmExportedFunction} provides the function index though,
which can be used to check whether code exists and access that code.

R=mstarzinger@chromium.org

Bug: v8:7758
Change-Id: Id80285fec46bf5be4af49875734aa0fe28d732c9
Reviewed-on: https://chromium-review.googlesource.com/1090273Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53576}

src/runtime/runtime-test.cc

@@ -1053,9 +1053,14 @@ RUNTIME_FUNCTION(Runtime_IsLiftoffFunction) {
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
   CHECK(WasmExportedFunction::IsWasmExportedFunction(*function));
-  wasm::WasmCode* wasm_code =
-      WasmExportedFunction::cast(*function)->GetWasmCode();
-  return isolate->heap()->ToBoolean(wasm_code->is_liftoff());
+  Handle<WasmExportedFunction> exp_fun =
+      Handle<WasmExportedFunction>::cast(function);
+  wasm::NativeModule* native_module =
+      exp_fun->instance()->compiled_module()->GetNativeModule();
+  uint32_t func_index = exp_fun->function_index();
+  return isolate->heap()->ToBoolean(
+      native_module->has_code(func_index) &&
+      native_module->code(func_index)->is_liftoff());
 }
 
 RUNTIME_FUNCTION(Runtime_CompleteInobjectSlackTracking) {

src/wasm/wasm-objects.cc

@@ -990,13 +990,6 @@ Handle<WasmExportedFunction> WasmExportedFunction::New(
   return Handle<WasmExportedFunction>::cast(js_function);
 }
 
-wasm::WasmCode* WasmExportedFunction::GetWasmCode() {
-  Address target = GetWasmCallTarget();
-  wasm::WasmCode* wasm_code =
-      GetIsolate()->wasm_engine()->code_manager()->LookupCode(target);
-  return wasm_code;
-}
-
 Address WasmExportedFunction::GetWasmCallTarget() {
   return instance()->GetCallTarget(function_index());
 }

src/wasm/wasm-objects.h

@@ -393,11 +393,6 @@ class WasmExportedFunction : public JSFunction {
                                           int func_index, int arity,
                                           Handle<Code> export_wrapper);
 
-  // TODO(clemensh): Remove this. There might not be a WasmCode object available
-  // yet.
-  // TODO(all): Replace all uses by {GetWasmCallTarget()}.
-  wasm::WasmCode* GetWasmCode();
-
   Address GetWasmCallTarget();
 };