Phase 7 followup: set equality in core-= + phs-to-struct

- phm.janet: add phs-to-struct (converts set to struct via phm-to-struct)
- core.janet: core-= now handles set? with phs-to-struct normalization
- test/phase7-test.janet: add (= #{1 2 3} #{3 2 1}) assertion
- 315 ok, 2 fail (pre-existing, unchanged)

src/jolt/core.janet

@@ -87,7 +87,10 @@
           (set ok
             (if (phm? a)
               (deep= (phm-to-struct a) (if (phm? b) (phm-to-struct b) b))
-              (if (phm? b) (deep= a (phm-to-struct b)) (deep= a b)))))
+              (if (phm? b) (deep= a (phm-to-struct b))
+                (if (set? a)
+                  (deep= (phs-to-struct a) (if (set? b) (phs-to-struct b) b))
+                  (if (set? b) (deep= a (phs-to-struct b)) (deep= a b)))))))
         (++ i))
       ok)))
 

src/jolt/phm.janet

@@ -194,3 +194,6 @@
 (defn phs-get [s x &opt default]
   (default default nil)
   (if (phm-contains? (s :phm) x) x default))
+
+(defn phs-to-struct [s]
+  (phm-to-struct (s :phm)))