message: recompute_instructions: Fix new-delete-type-mismatch
  Summary: Add missing virtual dtors.
  Test Plan: AddressSanitizer is happy.
  Reviewers: georgep, #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved
  Maniphest Tasks: T26151
diff: @@ -90,10 +90,12 @@ bool IsBackwardsConv(HloInstruction* inst) {
  }
  struct Replacer {
  + virtual ~Replacer() = default;
  virtual Status Replace() = 0;
  };
  struct Matcher {
  + virtual ~Matcher() = default;
  virtual std::unique_ptr<Replacer> PatternMatch(
  HloInstruction* inst) const = 0;
  };
  