`load-file` op: support both shapes, drop it, or break compat?

[bbatsov]

The spec's load-file op (with file-path) loads a file by path on the server side. The existing Clojure nREPL load-file works differently: it takes a file parameter containing the full source as a string and evaluates it inline, behaving close to eval.

@alexander-yakushev pointed out that this is a compatibility-breaking change, and that CIDER may soon replace its load-file usage with eval calls anyway.

@technomancy responded that a server could support both shapes (old behavior when file is present, new behavior when file-path is present), though he agrees the old behavior shouldn't be in the spec.

Options:

• Spec both shapes, with discovery rules.
• Drop load-file from the spec entirely and let clients use eval.
• Keep only the new shape and accept the compat break.