[wasm] Fix bug with empty input to Wasm.instantiateModuleFromAsm()

test/mjsunit/regress/regress-605488.js

Index: test/mjsunit/regress/regress-605488.js
diff --git a/test/mjsunit/call-intrinsic-type-error.js b/test/mjsunit/regress/regress-605488.js
similarity index 68%
copy from test/mjsunit/call-intrinsic-type-error.js
copy to test/mjsunit/regress/regress-605488.js
index 9d586977d924829f664a34c915440b5c8498dd63..31971d48445673d9dfd4456f69726e6be3edd3c6 100644
--- a/test/mjsunit/call-intrinsic-type-error.js
+++ b/test/mjsunit/regress/regress-605488.js
@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax
+// Flags:  --expose-wasm
 
 try {
-  %Call(1, 0);
+  Wasm.instantiateModuleFromAsm("");

[ahaas, 2016/05/03 09:58:04]

Could you add an assert(false) after instantiateModuleFromAsm to make sure that
an error was actually thrown?

 } catch (e) {
-  assertTrue(e instanceof TypeError);
+  print("Caught: " + e);
 }