Fix bug in power-of-two function in code-generator.  This caused an infinite loop with Word.* when multiplying by a constant with the highest bit set and not a power of two.
Fix bug in power-of-two function in code-generator.  This caused an infinite loop with Word.* when multiplying by a constant with the highest bit set and not a power of two.

git-svn-id: 98787b36aaefbae4b30fa755be920954cd25e1e4@1609 ae7d391e-3f74-4a2b-a0db-a8776840fd2a

polyml/polyml,polyml/polyml,mn200/polyml,dcjm/polyml,mn200/polyml,dcjm/polyml,mn200/polyml,mn200/polyml,polyml/polyml,polyml/polyml,dcjm/polyml,dcjm/polyml