[perl #126700] [JVM] calling index with negative start position on string does not return Nil

[Christian Bartolomaeus via RT]

After Rakudo commit negative start positions are disallowed:

$ perl6 -e 'say index("xxy", "y", -1).perl'
Failure.new(exception => X::OutOfRange.new(what => "Position in index", got => 
-1, range => "0..3", comment => Any), backtrace => Backtrace.new)

Tested in S32-str/index.t and S32-str/rindex.t

I'm closing this ticket as 'resolved'.