It's an "eval closure", not an "eval thunk." A thunk is a

It's an "eval closure", not an "eval thunk."  A thunk is a
function of no arguments.
* root.h (struct scm_root_state): Renamed
top_level_lookup_closure_var from top_level_lookup_thunk_var.
(scm_top_level_lookup_closure_var): Renamed from
scm_top_level_lookup_thunk_var.
* root.c (mark_root): Uses changed.
* gdbint.c (gdb_eval, gdb_binding): Uses changed.
* init.c (scm_start_stack): Uses changed.
* eval.c (scm_eval, scm_eval_x, scm_init_eval): Rename uses.
Change scheme-visible name to *top-level-lookup-closure* from
*top-level-lookup-thunk*.