osdep.h has a few things which are really compiler specific;
move them to compiler.h, and include compiler.h from osdep.h.
Backports commit 4912086865083a008f4fb73173fd0ddf2206c4d9 from qemu
Due to old Seabios bug, QEMU reenable LINT0 after reset. This bug is long gone
and therefore this hack is no longer needed. Since it violates the
specifications, it is removed.
Backports commit b8eb5512fd8a115f164edbbe897cdf8884920ccb from qemu
Since the BSP bit is writable on real hardware, during reset all the CPUs which
were not chosen to be the BSP should have their BSP bit cleared. This fix is
required for KVM to work correctly when it changes the BSP bit.
An additional fix is required for QEMU tcg to allow software to change the BSP
bit.
Backports commit 9cb11fd7539b5b787d8fb3834004804a58dd16ae from qemu
