[Cfp-interest] overflow to max normal

[David Hough CFP]

I wonder if we need an overflow alternate exception handling to overflow
to max normal rather than infinity.     I once had to deal with a customer
program that worked OK with max normal but not infinity.    It came from
a VAX.     I fixed it by changing the rounding direction to toward zero,
which fortunately didn't seem to adversely affect the rest of the program.

I didn't think to include that when we were drafting 754-2008 chapter 8.