fcl-res: fix missing field initialization in the coff writer, which in turn fixes fpcres randomly producing broken coff objects (rejected by GNU link)

packages/fcl-res/src/coffwriter.pp

@@ -423,6 +423,7 @@ begin
   st.SectionNumber:=1;
   st._type:=0;
   st.StorageClass:=fSymStorageClass;
+  st.NumAuxSymbol:=0;
   if OppositeEndianess then
     begin
       st.Value:=SwapEndian(st.Value);