ARMv7-A: use standard ARM core states

ARMv7-A: use standard ARM core states

We don't want an ARMv7-specific core state enumeration just to
add ThumbEE state.  Update the generic stuff to handle that,
and replace the V7-specific bits with it.

For Cortex-A8:  on debug entry, check both the T and J bits
instead of just the T bit.  When the J bit is set, set the
right state and warn appropriately.

(And while we're at it, move the generic arm struct to the front
of the v7a structure, for somewhat better code generation.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>