[wasm] JS API tests for `WebAssembly.validate`

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 1640 matching lines @@
             }
             int sig_index = table.map.FindOrInsert(function->sig);
             table_instance.signature_table->set(i, Smi::FromInt(sig_index));
             table_instance.function_table->set(i, *UnwrapImportWrapper(val));
           }
 
           num_imported_tables++;
           break;
         }
         case kExternalMemory: {
+          // Validation should have failed if more than one memory object was
+          // provided.
+          DCHECK(!instance->has_memory_object());
           if (!WasmJs::IsWasmMemoryObject(isolate_, value)) {
             ReportLinkError("memory import must be a WebAssembly.Memory object",
                             index, module_name, import_name);
             return -1;
           }
           auto memory = Handle<WasmMemoryObject>::cast(value);
           DCHECK(WasmJs::IsWasmMemoryObject(isolate_, memory));
           instance->set_memory_object(*memory);
           memory_ = Handle<JSArrayBuffer>(memory->buffer(), isolate_);
           break;
@@ skipping 649 matching lines @@
   CHECK(!compiled_module->has_weak_owning_instance());
 }
 
 void testing::ValidateOrphanedInstance(Isolate* isolate,
                                        Handle<WasmInstanceObject> instance) {
   DisallowHeapAllocation no_gc;
   WasmCompiledModule* compiled_module = instance->compiled_module();
   CHECK(compiled_module->has_weak_wasm_module());
   CHECK(compiled_module->ptr_to_weak_wasm_module()->cleared());
 }