[debugger] fix break locations for assignments and return.

test/mjsunit/es6/debug-stepnext-for.js

Index: test/mjsunit/es6/debug-stepnext-for.js
diff --git a/test/mjsunit/es6/debug-stepnext-for.js b/test/mjsunit/es6/debug-stepnext-for.js
index 932840a6f9247b4d799394abcee12a7a12e9b979..601487ec6282409038c86fef3dc45fe7feae9d26 100644
--- a/test/mjsunit/es6/debug-stepnext-for.js
+++ b/test/mjsunit/es6/debug-stepnext-for.js
@@ -91,7 +91,7 @@ print("log:\n"+ JSON.stringify(log));
 // based on other values.
 var expected = [
   // Entry
-  "a2","b2",
+  "a2",
   // Empty for-in-var: get enumerable
   "c16",
   // Empty for-in: get enumerable