kernel/util: Add self-link assertions to list_add_link_to_{head|tail}.

These caught the problem fixed in prior commits, and would have saved
me an awful lot of debugging time had they existed from the start.

They cannot catch all double-list-insertions, of course, but it's
relatively cheap to add these, and more than nothing.

kernel/util: Clear list links on removal under KDEBUG.

This way, if someone tries to double-remove an item or do other
invalid things to it, this will crash instead of (silently) corrupting.

kernel/util: Add static assert that the two list links are the same size.

They are used interchangeably in some places, so we should assert this.

kernel list: use BytePointer

Change-Id: I259cc33ad71cfbabc7f85278287a64a31dcb5e44
Reviewed-on: https://review.haiku-os.org/c/1101
Reviewed-by: waddlesplash <waddlesplash@gmail.com>

*.c -> *.cpp


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34417 a95241bf-73f2-0310-859d-f6bbb57e9c96

*.c -> *.cpp


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34417 a95241bf-73f2-0310-859d-f6bbb57e9c96