Fix gc memory leak

VersionedMap.cpp

@@ -5,6 +5,7 @@
 
 #include <assert.h>
 #include <atomic>
+#include <cstdint>
 #include <inttypes.h>
 #include <optional>
 #include <stdio.h>
@@ -338,6 +339,20 @@ struct MemManager {
     }
     next = max + 1;
 
+    for (int i = next; i < firstUnaddressable; ++i) {
+      if (base[i].entry != nullptr) {
+#if DEBUG_VERBOSE
+        if (debugVerboseEnabled) {
+          printf(
+              "Collecting %u while collecting right page-unaligned surplus\n",
+              i);
+        }
+#endif
+        base[i].entry->delref();
+        base[i].entry = nullptr;
+      }
+    }
+
     // Rebuild free list and delref entries
     freeList = 0;
     reachable.iterateAbsentApproxBackwards(