LowercasePatternMatchChecker should not warn when matched variable is used in result

[FlashSheridan]

In the examples for LowercasePatternMatchChecker, the lower-case match is obviously a mistake, since the variable masks an existing one, and is not used on the right side of the “=>”. But in scanning our existing code base, there were multiple reports where the code behaved as intended, and the match was actually used.
I accept that avoiding lower-case variables in this situation may be useful style for a new code base, but our uses are not actual semantic problems. It would be useful to be able to suppress these warnings, without suppressing genuine bugs where an existing variable is masked by a lower-case match.