for loop is unusable with types larger than usize

[FedericoStra]

Zig Version

0.12.0-dev.185+49075d205

Steps to Reproduce and Observed Behavior

The documentation for for vaguely says that

    // To iterate over consecutive integers, use the range syntax.
    // Unbounded range is always a compile error.
    var sum3 : usize = 0;
    for (0..5) |i| {
        sum3 += i;
    }
    try expect(sum3 == 10);

What it doesn't say is the important disclaimer that for only works for usize, which is a massive limitation.

For instance, the following seemingly innocent loops do not compile (in caso of tooBig assuming that usize is at most u64):

const std = @import("std");
const maxInt = std.math.maxInt;

pub fn negative() void {
    for (-1..0) |n|
        std.debug.print("{}\n", .{n});
}

pub fn tooBig() void {
    for (0..maxInt(u65)) |n|
        std.debug.print("{}\n", .{n});
}

test {
    std.testing.refAllDecls(@This());
}

❯ zig test src/for.zig 
src/for.zig:5:10: error: type 'usize' cannot represent integer value '-1'
    for (-1..0) |n|
         ^~
referenced by:
    refAllDecls__anon_1088: /.../zig/zig-linux-x86_64-0.12.0-dev.185+49075d205/lib/std/testing.zig:1129:14
    test_0: src/for.zig:15:28
    remaining reference traces hidden; use '-freference-trace' to see all reference traces
src/for.zig:10:19: error: type 'usize' cannot represent integer value '36893488147419103231'
    for (0..maxInt(u65)) |n|
            ~~~~~~^~~~~

Expected Behavior

Unsurprisingly, the expected behavior is that the for loop should be able to handle negative numbers and arbitrarily large integers.

I know that this kind of for loop is redundant and can always be reformulated in terms of while, but then what is the point of having such a limited construct which in many cases is either completely unusable or at best very cumbersome (requiring for instance @intCast/@truncate)?

[mlugg]

Duplicate of #17039 (I know the names imply slightly different things, but both issues really mean "types other than usize")