more testing fallout from core->std/std->extra move
auto merge of #6704 : tedhorst/rust/rename_lib_fixes, r=graydon

This passes make check now.
auto merge of #6705 : brson/rust/issue-5192, r=catamorphism

r? @catamorphism 

This could probably refactored to more closely mirror the code for `@objects`, but I'm not inclined to do so.
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