- Use correct offsets into the keys set array. As the elements of this

- Use correct offsets into the keys set array. As the elements of this
  zero-length array are dynamically sized at run-time based on the use
  of hints, compilers can't be expected to figure out these offsets on
  their own. [1]
- Fix incorrect comparison in cmp_nans(). [2]

PR:		204571 [1], 202301 [2]
Submitted by:	David Binderman [2]
MFC after:	3 days