Hi,
In preprocess_aggref(), list same_input_transnos is used to track compatible transnos.
Free it if we don’t need it anymore.
```
/*
* 2. See if this aggregate can share transition state with another
* aggregate that we've initialized already.
*/
transno = find_compatible_trans(root, aggref, shareable,
aggtransfn, aggtranstype,
transtypeLen, transtypeByVal,
aggcombinefn,
aggserialfn, aggdeserialfn,
initValue, initValueIsNull,
same_input_transnos);
list_free(same_input_transnos);
```
Not sure if it worths as it will be freed sooner or later when current context ends.
But as in find_compatible_agg(), the list is freed if we found a compatible Agg.
This patch helps a little when there are lots of incompatible aggs because we will try to find the compatible transnos again and again.
Each iteration will keep an unused list memory.
