score: Format <rtems/score/percpu.h>
smp: Provide cache optimized Per_CPU_Control

Delete _Per_CPU_Information_p.
tmtests/tm26: Fixes for RTEMS_DEBUG
sptests/sp37: Improved interrupt lock tests
score: Add and use ISR locks

ISR locks are low-level locks to protect critical sections accessed by
threads and interrupt service routines.

On single processor configurations the ISR locks degrade to simple ISR
disable/enable sequences.  No additional storage or objects are
required.

This synchronization primitive is supported on SMP configurations.  Here
SMP locks are used.