Enable strict mode testing for sm/Exceptions

test/staging/sm/Exceptions/error-expando-reconfigure.js

@@ -4,8 +4,6 @@
  */
 
 /*---
-flags:
-  - noStrict
 description: |
   Reconfiguring the first expando property added to an Error object shouldn't assert
 esid: pending

test/staging/sm/Exceptions/error-property-enumerability.js

@@ -4,12 +4,11 @@
  */
 
 /*---
-flags:
-  - noStrict
 description: |
   pending
 esid: pending
 ---*/
+
 var errors = ["Error", "EvalError", "RangeError", "ReferenceError",
               "SyntaxError", "TypeError", "URIError"];
 
@@ -33,4 +32,3 @@ for (var i = 0; i < errors.length; i++) {
   assert.sameValue(!!desc, true, "new " + errors[i] + "(...).message should exist");
   assert.sameValue((desc || {}).enumerable, false, "new " + errors[i] + "(...).message should not be enumerable");
 }
-