message: Remove C++17-only if-constexpr. Both paths will compile and the optimizer will
  remove the invalid path.
diff: @@ -46,7 +46,7 @@ class XStatsBuilder {
  }
  void AddStatValue(const XStatMetadata& metadata,
  unsigned long value) { // NOLINT
  - if constexpr (sizeof(unsigned long) == 8) { // NOLINT
  + if (sizeof(unsigned long) == 8) { // NOLINT
  AddStat(metadata)->set_uint64_value(value);
  } else {
  AddStat(metadata)->set_uint32_value(value);
  @@ -60,7 +60,7 @@ class XStatsBuilder {
  AddStat(metadata)->set_int64_value(value);
  }
  void AddStatValue(const XStatMetadata& metadata, long value) { // NOLINT
  - if constexpr (sizeof(long) == 8) { // NOLINT
  + if (sizeof(long) == 8) { // NOLINT
  AddStat(metadata)->set_int64_value(value);
  } else {
  AddStat(metadata)->set_int32_value(value);
  