Fix matching on Int[N] and UInt[N] in match statements.

[ghuls]

Fixes: #754

[arshajii]

Thanks for this PR, @ghuls. Could you please add a test for this? For convenience, I've written one below; you can paste this at the end of test/core/arithmetic.codon. Then I'll go ahead and merge!

@test
def test_int_match():
    n = 0
    match 42:
        case 0:
            n = 1
        case 42:
            n = 2
        case 100:
            n = 3
        case _:
            n = 4
    assert n == 2

    n = 0
    match u32(42):
        case u32(0):
            n = 1
        case u32(42):
            n = 2
        case u32(100):
            n = 3
        case _:
            n = 4
    assert n == 2

    n = 0
    match u32(99):
        case u32(0):
            n = 1
        case u32(42):
            n = 2
        case u32(100):
            n = 3
        case _:
            n = 4
    assert n == 4

    n = 0
    match i32(42):
        case i32(0):
            n = 1
        case i32(42):
            n = 2
        case i32(100):
            n = 3
        case _:
            n = 4
    assert n == 2

    n = 0
    match i32(99):
        case i32(0):
            n = 1
        case i32(42):
            n = 2
        case i32(100):
            n = 3
        case _:
            n = 4
    assert n == 4

test_int_match()

[ghuls]

@arshajii Added.

[arshajii]

Awesome, thanks! Merging now.