[Issue 19984] Support shared in foreach lambdas

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=19984

--- Comment #4 from Nicholas Wilson <iamthewilsonator at hotmail.com> ---
Hmm, point taken. It should be fairly easy to make opApply work with delegate
that are shared, see https://issues.dlang.org/show_bug.cgi?id=21737

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