[Cfp-interest] quiet vs signaling info disjoint from payload

[Jim Thomas]

This note satisfies an action item from today's CFP teleconference and 
confirms that NaN payloads do not contain any of the bits used to 
determine if a NaN is quiet vs signaling.

For decimal formats (both encodings), 3.5.2 says the payload is 
contained in the trailing significand field T, while the (disjoint) 
combination field G determines NaN-ness and quiet vs signaling.

For binary formats, 6.2.1 says "NaNs have a sign bit and a pattern of 
bits necessary to identify the encoding as a NaN and which determines 
its kind (sNaN vs qNaN). The remaining bits, which are in the trailing 
significand field, encode the payload ..."

-Jim