1585db458f
Before the patch, `writeCombinedGlobalValueSummary` traversed entire `cfiFunction*` for each module, just to pick a few symbols from `DefOrUseGUIDs`. Now we change internals of `cfiFunctionDefs` and `cfiFunctionDecls` to maintain a map from GUID to StringSet. So now we iterate `DefOrUseGUIDs`, usually small, and pick exact subset of symbols. Sorting is not strictly necessary, but it preserves the order of emitted values.