Fix copy-more-arg on ARM.
Improve testing for subtypes of 1-dimensional simple-arrays

This needs some additional work for platforms other than x86[-64].

Also sprinkle around some meta-comments about obsolete comments.
Addendum to previous change which added SIMPLE-RANK-1-ARRAY-*-P
One more omission from widetag tests. Third time's the charm?
Adjust control-stack size on ARM.

Now that copy-more-arg is fixed, it can be reduced, set size to 2 and
size-increment to 1.
More immediate encoding fixes on ARM.

This time dealing with large stack frames.