...as flagged by -fsanitize=undefined.  But is it really undefined?
[conv.double] "If the source value is between two adjacent destination values,
the result of the conversion is an implementation-defined choice of either of
those values."  So if the double is between std::numeric_limits<float>::max()
and std::numeric_limits<float>::infinity()...

Change-Id: I6389c8ac4a922991e240638d231dd2a39e173882