Test GRUB2 compiled by MingW

[Hanzac Chen]

Hi,

After I get the GRUB2 successfully compiled by MingW (since it now can
handle binary output with its latest version of binutils), I can't boot
it after making the image according to the README.

1. boot it with QEMU, got "GRUB loading kernel..." then it seemed to be
dead.
2. boot it with Bochs, got a little bit further and displayed "no upper
memory".

BTW: When generate the kernel_syms.lst, every symbol should have a
underline at the beginning when compiling with some kind of compiler
like MingW.

Bye,
Hanzac