checker: fix match expr with auto promote number (fix #21624)

[yuyi98]

This PR fix match expr with auto promote number (fix #21624).

• Fix match expr with auto promote number.
• Add test.

// convert strings like 10K to i164
const block = 512
// const block = i64(512)

// **1
const kilo = i64(1024)
const kilobyte = i64(1000)

// **2
const mega = kilo * kilo
const megabyte = kilobyte * kilobyte

// **3
const giga = mega * kilo
const gigabyte = megabyte * kilobyte

// **4
const terra = giga * kilo
const terrabyte = gigabyte * kilobyte

// **5
const peta = mega * kilo
const petabyte = megabyte * kilobyte

// **6
const exa = peta * kilo
const exabyte = peta * kilo

// **7
const zetta = exa * kilo
const zettabyte = exabyte * kilobyte

// **8
const yotta = zetta * kilo
const yottabyte = zettabyte * kilobyte

// **9
const ronna = yotta * kilo
const ronnabyte = yottabyte * kilobyte

// **10
const quetta = ronna * kilo
const quettabyte = ronnabyte * kilobyte

fn string_to_i64(s string) ?i64 {
    if s.len == 0 {
        return none
    }

    mut index := 0
    for index < s.len {
        match true {
            s[index].is_digit() {}
            s[index] == `+` && index == 0 {}
            s[index] == `-` && index == 0 {}
            else { break }
        }
        index += 1
    }

    number := s[0..index].i64()
    suffix := if index < s.len { s[index..] } else { 'c' }

    multiplier := match suffix.to_lower() {
        'b' { block }
        'k' { kilo }
        'kb', 'kib' { kilobyte }
        'm' { mega }
        'mb', 'mib' { megabyte }
        'g' { giga }
        'gb', 'gib' { gigabyte }
        't' { terra }
        'tb', 'tib' { terrabyte }
        'p' { peta }
        'pb', 'pib' { petabyte }
        'e' { exa }
        'eb', 'eib' { exabyte }
        'z' { zetta }
        'zb', 'zib' { zettabyte }
        'y' { yotta }
        'yb', 'yib' { yottabyte }
        'r' { ronna }
        'rb', 'rib' { ronnabyte }
        'q' { quetta }
        'qb', 'qib' { quettabyte }
        // oddball formats found in __xstrtol source
        'c' { 1 }
        'w' { 2 }
        else { return none }
    }

    result := number * multiplier
    if result == 0 && number != 0 {
        return none
    }
    return result
}

fn main() {
    assert string_to_i64('19P')! == 19 * peta
    assert string_to_i64('18T')! == 18 * terra
}

PS D:\Test\v\tt1> v run .