I tend to err on the side of more tests, but it's not entirely clear that the test is worthwhile here.
LGTM
*** Submitted as http://code.google.com/p/go/source/detail?r=66621dd2e8fa *** json: fix addressing of slice indexes that are multiples of 8. Fixes issue 147. R=rsc CC=golang-dev http://codereview.appspot.com/152123