SERVER-82228 introduced unwanted copying through use of "auto" when "auto&" was probably intended.

E.g. run_aggregate.cpp parsePipelineAndRegisterQueryState() now has line

auto requestForQueryStats = aggExState.getOriginalRequest(); 

getOriginalRequest() returns const AggregateCommandRequest& but assigning it to "auto" will drop the "&" and copy the object into requestForQueryStats.

There may be more similar unintended copies - I just noticed this one.