- Register a fn under the name Chez actually reports for its frame, not the def
name: a named fn literal whose name differs from the def (def foo (fn bar …))
is framed as 'bar', and an anonymous fn def (def foo (fn …)) as jv$ns$foo.
Both previously registered under the def name and so never appeared in traces.
- rdr-source-file / rdr-pos-cursor are thread parameters, so concurrent compiles
(futures, core.async) don't clobber each other's file/line attribution.
- Read JOLT_DEBUG_FRAMES at call time: a built binary evaluates top-level forms
at heap-build time, where a load-time getenv is always unset.
Re-mint (backend + reader); prelude byte-identical, selfhost holds.
8d7008b232