Remove the hardcoded bit definitions in the tmpalias assembly code.
This makes it easy to change the size of the tmpalias region.

The alignment of the tmpalias region is reduced from 16 MB to 8 MB.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>