Function measure_size_classes 

pub fn measure_size_classes(
    info: &HardwareInfo,
    mcfg: &MeasurementConfig,
    min_improvement: f64,
    filter: &[String],
) -> Result<(Vec<SizeClassEntry>, Vec<TournamentResult>)>

Measure memscan/copy variants across L1/L2/L3/DRAM; return HNEP size-class entries.