GC: fixes size computation for leak detection
GC: fixes size computation for leak detection

russpowers/Nim,dom96/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,dom96/Nim,russpowers/Nim,russpowers/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,dom96/Nim