rework nimOrcLeakDetector (#24958)

ref #22273 (comment)

Author: ringabout

lib/system.nim

@@ -1616,7 +1616,7 @@ when not defined(js) and defined(nimV2):
       align: int16
       depth: int16
       display: ptr UncheckedArray[uint32] # classToken
-      when defined(nimTypeNames) or defined(nimArcIds):
+      when defined(nimTypeNames) or defined(nimArcIds) or defined(nimOrcLeakDetector):
         name: cstring
       traceImpl: pointer
       typeInfoV1: pointer # for backwards compat, usually nil