Fix computed properties on object literals with a double as propertyname.

test/mjsunit/regress/regress-double-property.js

Index: test/mjsunit/regress/regress-double-property.js
diff --git a/test/mjsunit/regress/regress-crbug-351262.js b/test/mjsunit/regress/regress-double-property.js
similarity index 78%
copy from test/mjsunit/regress/regress-crbug-351262.js
copy to test/mjsunit/regress/regress-double-property.js
index a2f4eadc0de5c2bd7d27f6e78ff9940fce7b0f85..2ddb45b4b66c79600c78abfaf5b64c1a9a13927a 100644
--- a/test/mjsunit/regress/regress-crbug-351262.js
+++ b/test/mjsunit/regress/regress-double-property.js
@@ -2,5 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-for (var x in this) {};
-JSON.stringify(this);
+function f(a) {
+  return {0.1: a};
+}
+
+f();