bugfix? LGC should never clear a suspect...

Previously, LGC was attempting to unpin objects and then unmark them
as suspects. This is not correct -- it's possible for a suspect to
be in scope of LGC, and it should remain a suspect, because LGC can
have one or more ancestor heaps in scope. (So, for example, an
ancestor object that contains a down-pointer would be marked as
suspect, could be in-scope of the LGC, and should remain a suspect.)

runtime/gc/hierarchical-heap-collection.c

@@ -75,12 +75,6 @@ static inline HM_HierarchicalHeap toSpaceHH (GC_state s, struct ForwardHHObjptrA
 static bool try_disentangle_object(objptr op, uint32_t opDepth) {
   if (isPinned(op) && unpinDepthOf(op) >= opDepth) {
     bool successful_unpin = tryUnpinWithDepth(op, opDepth);
-    if (successful_unpin && ES_contains(NULL, op)) {
-      LOG(LM_HIERARCHICAL_HEAP, LL_INFO,
-          "disentangling a suspect at depth %u",
-          opDepth);
-      return try_clear_suspect(op, opDepth);
-    }
     return successful_unpin;
   }
   return TRUE;