message: [XLA] Delete dead function in hlo_graph_dumper.
  No functional change.
diff: @@ -112,11 +112,6 @@ class NodeFilter {
  result == kSomeUsersOmitted;
  }
  - bool ShowFusionSubcomputation(const HloInstruction* instr) const {
  - CHECK_EQ(instr->opcode(), HloOpcode::kFusion);
  - return Show(instr) && !SomeOrAllOperandsOmitted(instr);
  - }
  -
  private:
  std::function<NodeFilterResult(const HloInstruction* instr)> filter_;
  };
  