That was a tough one to debug! I almost thought it was a bug in fennel,
but it, of course, turned out to be a fennel-ls problem.
When you have a symbol like (foo:bar), fennel compiles it by
"macroexpanding" it to (: foo :bar). When fennel macroexpands a macro,
it tries to clean up the output by giving it a best-guess
bytestart/byteend. Fennel-ls was picking up *both* the accurate
`foo:bar` sym and the best-guess virtual `foo` sym as separate
references to `foo`. When computing the renames, the best-guess values
were getting used, which made the replacement range inaccurate.
6f9935a781