test: fold phase ports into spec; promote compile-mode test

Mine the phase* port batteries into the spec layer and delete them (their
behavior is now covered by spec): phase5 (hierarchies), phase6 (tagged
literals/reader-conditionals), phase7 (lazy/sets), phase8+phase12 (protocols;
phase12 was a duplicate of phase8), phase10 (strings/set), phase13
(reify/walk). Unique cases mined into spec: reader #inst/#uuid/#?@ splice,
(Type. args) dot constructor, lazy-seq body-runs-once, keywordize-keys/
stringify-keys, custom :default key and explicit :hierarchy dispatch.

phase6-final tested the COMPILE-MODE path ({:compile? true}), distinct from the
interpreter-based spec — kept and renamed integration/compile-mode-test.

jpm test green, conformance 218/218.

test/spec/reader-syntax-spec.janet

@@ -33,6 +33,9 @@
   ["discard #_"         "[1 3]"     "[1 #_2 3]"]
   ["regex literal"      "true"      "(= \"abc\" (re-find #\"abc\" \"xabcx\"))"]
   ["reader conditional" "1"         "#?(:clj 1 :cljs 2 :default 3)"]
+  ["reader cond splice" "[1 2 3]"   "[#?@(:clj [1 2 3] :cljs [4 5])]"]
+  ["inst literal reads" "true"      "(some? #inst \"2020-01-01T00:00:00Z\")"]
+  ["uuid literal"       "\"550e8400-e29b-41d4-a716-446655440000\"" "(str #uuid \"550e8400-e29b-41d4-a716-446655440000\")"]
   ["tagged literal var" "true"      "(var? #'+)"]
   ["deref sugar"        "5"         "(let [a (atom 5)] @a)"]
   ["meta sugar"         "{:t 1}"    "(meta ^{:t 1} [])"])