InteractiveEval constructs Uniques in a grimy manner
There are two places in InteractiveEval which create a Unique from the FastString unique field.
A fresh unique needs to be generated properly in both compileParsedExprRemote and bindLocalsAtBreakpoint both get an integer from the FastString unique and use that to make a Unique. Making a Unique from a FastString unique is not safe, they count different things.