  implement transparent bounds.  Ticket #6067 

Issue created from code comment with imdone.io

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TODO:   implement transparent bounds.  Ticket #6067 id:295
[**deps/icu-small/source/i18n/rematch.cpp:3922**](https://github.com/imdone/node/blob/9e8f4b3834263f0c66fb0f5483c4284a4d8ea682/deps/icu-small/source/i18n/rematch.cpp#L3922)
