[perl #64804] tainting breakage with index() of a constant

Bug affects recent stable version 5.14.2.

Maybe we should add a regression test.

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via perlbug:  queue: perl5 status: resolved
https://rt.perl.org:443/rt3/Ticket/Display.html?id=64804

• [perl #64804] tainting breakage with index() of a constant by Mark via RT
• Re: [perl #64804] tainting breakage with index() of a constant by Dave Mitchell