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

test/inspector/debugger/wasm-stack.js

 // 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.
 
 // Flags: --expose-wasm
 
 load('test/mjsunit/wasm/wasm-constants.js');
 load('test/mjsunit/wasm/wasm-module-builder.js');
 
 var builder = new WasmModuleBuilder();
 
-var imported_idx = builder.addImport("func", kSig_v_v);
+var imported_idx = builder.addImport("mode", "func", kSig_v_v);
 
 var call_imported_idx = builder.addFunction('call_func', kSig_v_v)
   .addBody([kExprCallFunction, imported_idx])
   .index;
 
 // Open a block in order to make the positions more interesting...
 builder.addFunction('main', kSig_v_v)
   .addBody(
     [kExprBlock, kAstStmt, kExprCallFunction, call_imported_idx, kExprEnd])
   .exportAs('main');
 
 var module_bytes = builder.toArray();
 
 function testFunction(bytes) {
   function call_debugger() {
     debugger;
   }
 
   var buffer = new ArrayBuffer(bytes.length);
   var view = new Uint8Array(buffer);
   for (var i = 0; i < bytes.length; i++) {
     view[i] = bytes[i] | 0;
   }
 
   var module = new WebAssembly.Module(buffer);
-  var instance = new WebAssembly.Instance(module, {func: call_debugger});
+  var instance = new WebAssembly.Instance(module, {mode: {func: call_debugger}});
 
   instance.exports.main();
 }
 
 InspectorTest.addScript(testFunction.toString());
 
 Protocol.Debugger.enable();
 Protocol.Debugger.onPaused(handleDebuggerPaused);
 InspectorTest.log('Running testFunction with generated WASM bytes...');
 Protocol.Runtime.evaluate(
@@ skipping 38 matching lines @@
 {
   InspectorTest.log(
       'Result of evaluate (' + response.result.result.type + '):');
   var result_lines = response.result.result.value.split('\n');
   // Skip the second line, containing the 'evaluate' position.
   result_lines[1] = '    -- skipped --';
   InspectorTest.log(result_lines.join('\n'));
   InspectorTest.log('Finished!');
   InspectorTest.completeTest();
 }