0.8.13.34:

0.8.13.34:
	* Start using Helmut Eller's cute computed features expression
	  to distinguish between 32-bit and 64-bit pieces of code.
	  Particularly useful because architecture names are not
	  hardcoded; this idiom may have to be squirreled away in a
	  function somewhere.
	* SB!VM:WORD-SHIFT and SB!VM:N-WORD-BYTES were being defined
	  the same way in every backend; move their definitions to
	  generic/early-vm for MORE OOAO.  Tidy up comments in various
	  backends for remaining constants--you can almost see the
	  common code cut-and-pasted in each backend...