Avoid shift equal to bits in type (caused endless loop).

Avoid shift equal to bits in type (caused endless loop).

Also clean up comparisons between different types, and some odd
indentation problems that showed up somehow.

A new endless loop was introduced by the clang compiler, which
apparently does odd things when the right operand of << is equal to
or greater than the number of bits in the type.  The C standard in
fact states that the behavior of << is undefined in that case.  The
loop was rewritten to use single-bit shifts.