nimkernel broken when use Clang with -d or -opt flags
Hello, 

I had some experiment with you code, that was fun and thank for creating this example. I try to use Clang with you kernel with exact config you do, some function broken weirdly and loop QEMU BIOS when i use flag like -d:release or -opt:speed the kernel goes to that state, but it totally fine without any -d or -opt. 

I trace the culprit belong to this line : https://github.com/ArjunRangga/nimkernel/blob/clang/ioutils.nim#L77 , when it invoked by kmain.

Here my code : https://github.com/ArjunRangga/nimkernel/tree/clang .

Do you had idea what happen ? or I miss something? Anyways, It pass compilation either with flags or not. 
