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

test/inspector/debugger/wasm-source.js

Index: test/inspector/debugger/wasm-source.js
diff --git a/test/inspector/debugger/wasm-source.js b/test/inspector/debugger/wasm-source.js
index 0a77c19ac40fc07615c5b4f5bf439730d9076005..6d9d044b30c5978e67f47efd45e4bca1cf4ae8f0 100644
--- a/test/inspector/debugger/wasm-source.js
+++ b/test/inspector/debugger/wasm-source.js
@@ -9,7 +9,7 @@ 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("xxx", "func", kSig_v_v);
 
 var call_imported_idx = builder.addFunction("call_func", kSig_v_v)
     .addBody([kExprCallFunction, imported_idx])
@@ -40,7 +40,7 @@ function testFunction(bytes) {
   }
 
   var module = new WebAssembly.Module(buffer);
-  var instance = new WebAssembly.Instance(module, {func: call_debugger});
+  var instance = new WebAssembly.Instance(module, {xxx: {func: call_debugger}});
 
   instance.exports.main();
 }