Section and type conversion inside a function blows up section size

Given the following pattern:

import std.mem;

#pragma array_limit -1

union StringToByteConverter<auto size>
{
    u8 data[size];
    str val;
};

fn main()
{
    u128 size = 2;

    auto fileSection = std::mem::create_section("file");

    StringToByteConverter<size> converter @ 0x0 in fileSection;

    converter.val = "a" * size;
};

it would be expected for the "file" section to have a size of 0x2. Instead it has a size of 0x40000002.

Moving the code to global scope (so outside of main) resolves this issue.

Issue verified by AxCut on Discord.

Start by running the provided main function with std::mem::create_section and compare its section size with the equivalent code at global scope. Trace how StringToByteConverter and converter.val affect the file section, then verify that the reproduced case reports a size of 0x2 rather than 0x40000002.