message: [XLA] Initialize fields of RematerializationSizes by default
diff: @@ -45,8 +45,8 @@ class HloRematerialization : public HloModulePass {
  // Helper struct that communicates the before / after sizes for the
  // rematerialization process.
  struct RematerializationSizes {
  - int64 before_bytes;
  - int64 after_bytes;
  + int64 before_bytes = -1;
  + int64 after_bytes = -1;
  };
  // Mode in which the rematerialization algorithm should be run.
  