[wasm] Implement correct 2-level namespace for imports.

src/wasm/wasm-module.cc

 // Copyright 2015 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 <memory>
 
 #include "src/assembler-inl.h"
 #include "src/base/adapters.h"
 #include "src/base/atomic-utils.h"
 #include "src/code-stubs.h"
@@ skipping 1391 matching lines @@
 
     // Look up the module first.
     MaybeHandle<Object> result =
         Object::GetPropertyOrElement(ffi_, module_name);
     if (result.is_null()) {
       return ReportTypeError("module not found", index, module_name);
     }
 
     Handle<Object> module = result.ToHandleChecked();
 
-    // TODO(bradnelson): Making this conditional on non-empty names violates the
-    // Wasm spec, but seems to be a hack intended for the asm-to-wasm pipeline.
-    // We need to get rid of it.
-    if (import_name->length() != 0) {
-      // Look up the value in the module.
-      if (!module->IsJSReceiver()) {
-        return ReportTypeError("module is not an object or function", index,
-                               module_name);
-      }
+    // Look up the value in the module.
+    if (!module->IsJSReceiver()) {
+      return ReportTypeError("module is not an object or function", index,
+                             module_name);
+    }
 
-      result = Object::GetPropertyOrElement(module, import_name);
-      if (result.is_null()) {
-        ReportLinkError("import not found", index, module_name, import_name);
-        return MaybeHandle<JSFunction>();
-      }
+    result = Object::GetPropertyOrElement(module, import_name);
+    if (result.is_null()) {
+      ReportLinkError("import not found", index, module_name, import_name);
+      return MaybeHandle<JSFunction>();
     }
 
     return result;
   }
 
   uint32_t EvalUint32InitExpr(const WasmInitExpr& expr) {
     switch (expr.kind) {
       case WasmInitExpr::kI32Const:
         return expr.val.i32_const;
       case WasmInitExpr::kGlobalIndex: {
@@ skipping 878 matching lines @@
   CHECK(!compiled_module->has_weak_owning_instance());
 }
 
 void testing::ValidateOrphanedInstance(Isolate* isolate,
                                        Handle<WasmInstanceObject> instance) {
   DisallowHeapAllocation no_gc;
   WasmCompiledModule* compiled_module = instance->get_compiled_module();
   CHECK(compiled_module->has_weak_wasm_module());
   CHECK(compiled_module->ptr_to_weak_wasm_module()->cleared());
 }