Move most arch/i386 files to arch/x86, and adjust the contents of the
Makefiles and the include/bits/*.h headers to reflect the new
locations.

This patch makes no substantive code changes, as can be seen using a
rename-aware diff (e.g. "git show -M5").

This patch does not make the pcbios platform functional for x86_64; it
merely allows it to compile without errors.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Signed-off-by: Michael Brown <mcb30@ipxe.org>

Add FILE_LICENCE declarations to almost all files that make up the
various standard builds of gPXE.

COMBOOT images use INTs to issue API calls; these end up making calls
into gPXE from real mode, and so temporarily change the real-mode
stack pointer.  When our COMBOOT code uses a longjmp() to implement
the various "exit COMBOOT image" API calls, this leaves the real-mode
stack pointer stuck with its temporary value, which causes problems if
we eventually try to exit out of gPXE back to the BIOS.

Fix by adding rmsetjmp() and rmlongjmp() calls (analogous to
sigsetjmp()/siglongjmp()); these save and restore the additional state
needed for real-mode calls to function correctly.

__cdecl is a misleading name, since it currently encapsulates both
cdecl and regparm(0) attributes.  Rename to __asmcall.