gpgscm: Optimize environment lookups and insertions.
* tests/gpgscm/scheme.c (pointercmp): New function. (new_slot_spec_in_env): Add and use slot for insertions. (find_slot_spec_in_env): New variant of 'find_slot_in_env' that returns the slot on failures. (find_slot_in_env): Express using the new function. (new_slot_in_env): Update callsite. (opexe_0): Optimize lookup-or-insert. (opexe_1): Likewise. (scheme_define): Likewise.
Optimize environment lookups by keeping the lists in the hash table or
the list sorted. Optimize the insertions by passing the slot computed
by the lookup to the insertion.
- Signed-off-by: Justus Winter <firstname.lastname@example.org>