Due to similar padding issue as pipe, the list of task object
may not be used directly. As mentioned before, some compiler/linker
may pad the large struct. For example, compiling under gcc and
march=i686 pads the struct to 32-byte alignment (march=atom to
64-byte alignment). This causes issue with sizeof() and pointer
arithmetic because they have no idea about the padding.
When the stars align in a certain way, these task structs may be
corrupted. So add a task pointer list and use it for task
manipulation. The task list remains as it is beneficial to group
them together to take advantage of cache locality.
Change-Id: I0e86bfe05742040f4540d7854c1ac14e76162776
Signed-off-by: Daniel Leung <daniel.leung@intel.com>