[wasm] Support a two-level namespace for imports.

test/unittests/wasm/module-decoder-unittest.cc

Index: test/unittests/wasm/module-decoder-unittest.cc
diff --git a/test/unittests/wasm/module-decoder-unittest.cc b/test/unittests/wasm/module-decoder-unittest.cc
index c32e873ef8dde2d8e4d78148165445727df0bd8e..d7dbbd7dbeaf7d069996ab080fa76c66a16429b0 100644
--- a/test/unittests/wasm/module-decoder-unittest.cc
+++ b/test/unittests/wasm/module-decoder-unittest.cc
@@ -388,7 +388,6 @@ TEST_F(WasmModuleVerifyTest, OneFunctionImported) {
   if (result.val) delete result.val;
 }
 
-
 TEST_F(WasmModuleVerifyTest, OneFunctionWithNopBody) {
   static const byte kCodeStartOffset = 19;
   static const byte kCodeEndOffset = kCodeStartOffset + 1;
@@ -1095,6 +1094,20 @@ TEST_F(WasmModuleVerifyTest, ImportTable_one_sig) {
   EXPECT_VERIFIES(data);
 }
 
+TEST_F(WasmModuleVerifyTest, ImportTable_invalid_module) {
+  static const byte data[] = {
+      kDeclSignatures,
+      1,
+      VOID_VOID_SIG,
+      kDeclImportTable,
+      1,               // --
+      SIG_INDEX(0),    // sig index
+      NAME_OFFSET(0),  // module name
+      NAME_OFFSET(1)   // function name
+  };
+  EXPECT_FAILURE(data);
+}
+
 TEST_F(WasmModuleVerifyTest, ImportTable_off_end) {
   static const byte data[] = {
       kDeclSignatures, 1, VOID_VOID_SIG, kDeclImportTable, 1,