Find another workaround for the PHP bug #65136.

The previous fix did not work in rare cases. This fix seems to work
well. It avoids a seg fault and a bus error (when compiled with
--enable-dtrace).
[auto] Merge from Iterator

    • #2df6f61 — Find another workaround for the PHP bug #65136. (Ivan Enderlin, 2013-07-05)

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Merge remote branch 'library-iterator/master'