The current organization of the x86 documentation makes it appear as
if the "i386" documentation doesn't apply to x86-64, which is does.
Thus, move that documentation into Documentation/x86, and move the
x86-64-specific stuff into Documentation/x86/x86_64 with the eventual
goal to move stuff that isn't actually 64-bit specific back into
Documentation/x86.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Fix typos.
Lots of whitespace changes for readability and consistency.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndi Kleen <ak@suse.de>

Describes the stack organization on x86-64.

I changed it a bit and removed some obsolete information and the
questions.

Cc: kaos@sgi.com
Signed-off-by: NAndi Kleen <ak@suse.de>