gc:destructors progress

lib/system/hti.nim

@@ -87,20 +87,28 @@ type
     ntfEnumHole = 2    # enum has holes and thus `$` for them needs the slow
                        # version
   TNimType {.compilerproc.} = object
+    when defined(gcDestructors):
+      head*: pointer
     size: int
     kind: TNimKind
     flags: set[TNimTypeFlag]
     base: ptr TNimType
     node: ptr TNimNode # valid for tyRecord, tyObject, tyTuple, tyEnum
-    finalizer: pointer # the finalizer for the type
-    marker: proc (p: pointer, op: int) {.nimcall, benign.} # marker proc for GC
+    finalizer*: pointer # the finalizer for the type
+    marker*: proc (p: pointer, op: int) {.nimcall, benign.} # marker proc for GC
     deepcopy: proc (p: pointer): pointer {.nimcall, benign.}
     when defined(nimTypeNames):
       name: cstring
       nextType: ptr TNimType
       instances: int # count the number of instances
       sizes: int # sizes of all instances in bytes
-  PNimType = ptr TNimType
+
+when defined(gcDestructors):
+  type
+    PNimType* = ptr TNimType
+else:
+  type
+    PNimType = ptr TNimType
 
 when defined(nimTypeNames):
   # Declare this variable only once in system.nim