os_bootinfo is now bundled with the bootloader

[phil-opp]

This means that we no longer have version mismatches (provided that the kernel uses the re-export and not the os_bootinfo crate directly). This means that we can drop the VERSION constant and the repr(C) requirement of the BootInfo struct.

The question is whether we want to do this. It would bound the bootloader to Rust kernels. It would also be a backwards compatibility hazard because there might be still kernels that use os_bootinfo directly.

[phil-opp]

See rust-osdev/bootloader#23