Fix for pr2148500.
Fix for pr2148500.

This patch fixes the expression width calculation for a multiply
operation with an unsized operation. The expression width needs
to be at least the minimum of the maximum multiply result width
and the width of an integer.

CastMi/iverilog,CastMi/iverilog,themperek/iverilog,CastMi/iverilog,themperek/iverilog,themperek/iverilog