Cast some expressions that multiply a long long constant by a
floating point constant to int64_t. This avoids the runtime
conversion of the the other operand in a set of comparisons from
int64_t to floating point and doing the comparisions in floating
point.

Suggested by: lidl
Submitted by: Rasool Al-Saadi <ralsaadi@swin.edu.au>
MFC after: 2 weeks (with r300779)