memory: Align MemoryRegionSections fields

memory: Align MemoryRegionSections fields

MemoryRegionSection includes an Int128 'size' field;
on some platforms the compiler causes an alignment of this to
a 128bit boundary, leaving 8 bytes of dead space.
This deadspace can be filled with junk.

Move the size field to the top avoiding unnecessary alignment.

Signed-off-by: Dr. David Alan Gilbert <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <20190814175535[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>