rounding (impl. dep. #55), the SPARC JPS1 responsible for SPARC64 and
UltraSPARC processors defines that in all cases tinyness is detected
before rounding, therefore rounding up to the smallest normalised
number should set the underflow flag.
- If an infinite result is rounded down, the result should have an
exponent 1 less than the value for infinity.
PR: 144900
Submitted by: Peter Jeremy
MFC after: 3 days