identAsString

fn identAsString(astgen: *AstGen, ident_token: Ast.TokenIndex) !Zir.NullTerminatedString {
    const gpa = astgen.gpa;
    const string_bytes = &astgen.string_bytes;
    const str_index: u32 = @intCast(string_bytes.items.len);
    try astgen.appendIdentStr(ident_token, string_bytes);
    const key: []const u8 = string_bytes.items[str_index..];
    const gop = try astgen.string_table.getOrPutContextAdapted(gpa, key, StringIndexAdapter{
        .bytes = string_bytes,
    }, StringIndexContext{
        .bytes = string_bytes,
    });
    if (gop.found_existing) {
        string_bytes.shrinkRetainingCapacity(str_index);
        return @fromBackingInt(@intCast(gop.key_ptr.*));
    } else {
        gop.key_ptr.* = str_index;
        try string_bytes.append(gpa, 0);
        return @fromBackingInt(@intCast(str_index));
    }
}