This patch refreshes support for ARM (arm-uboot is a prerequisite).

A number of common instructions used by the kernel were added to
5[al]: SVC, WFE, WFI, ERET, CPS, CPSID, CPSIE, DMB, DSB, and ISB.

Support for the link register in the grammar was added (LR) and the
arm acid library was updated to better reflect register state.  r15 in
the Ureg structure was also changed to a union of r15 and pc, similar
to link and sp.

Formal support for coprocessor registers was added as well.  This
brings 5a a touch closer to UAL and provides some modicum of
validation.  This change required updating use of coprocessor
registers in each of the current ARM ports: bcm, kw, omap, and teg2.

Finally, a number of bugs were corrected in 5db; disassembly output is
now correct.