[src] Further optimizations to Parrot_byte_index() thanks to feedback from Andy Dougherty.  Using memchr() instead of strchr() is a further gain.  This code is now about seven times faster than it was, per the regex tests as a benchmark.
[src] Further optimizations to Parrot_byte_index() thanks to feedback from Andy
Dougherty.  Using memchr() instead of strchr() is a further gain.  This code is now about seven times faster than it was, per the regex tests as a benchmark.

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@21844 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

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