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

test/mjsunit/wasm/data-segments.js

Index: test/mjsunit/wasm/data-segments.js
diff --git a/test/mjsunit/wasm/data-segments.js b/test/mjsunit/wasm/data-segments.js
index 8cff5e17567620c26ebaf37e1fd81b039899536b..b215f20857e8d359ce7066a50cbff988600d1056 100644
--- a/test/mjsunit/wasm/data-segments.js
+++ b/test/mjsunit/wasm/data-segments.js
@@ -39,7 +39,7 @@ function GlobalImportedInitTest(pad) {
 
   while (pad-- > 0) builder.addGlobal(kAstI32);  // pad
 
-  var g = builder.addImportedGlobal("offset", undefined, kAstI32);
+  var g = builder.addImportedGlobal("mod", "offset", kAstI32);
 
   while (pad-- > 0) builder.addGlobal(kAstI32);  // pad
 
@@ -52,7 +52,7 @@ function GlobalImportedInitTest(pad) {
   var module = new WebAssembly.Module(buffer);
 
   for (var offset of [0, 12, 192, 1024]) {
-    var instance = new WebAssembly.Instance(module, {offset: offset});
+    var instance = new WebAssembly.Instance(module, {mod: {offset: offset}});
     for (var i = offset - 20; i < offset + 20; i += 4) {
       if (i < 0) continue;
       var expected = i == offset ? 84215045 : 0;