repl,test: no test coverage for .scope

[bnoordhuis]

repl.markdown says:

On tab completion - eval will be called with .scope as an input string.

In #3544, neither @Trott nor yours truly could make it work and there doesn't appear to be test coverage.

/cc @TooTallNate

[Trott]

I believe #5534 fixes this. Closing. Feel free to re-open if I'm misunderstanding.