Avoid large operands in constant folding.
Avoid large operands in constant folding.

We already have code that counts the total size of operands. However it still
has a check that the number of users of an operand is 1. This stems from a time
where we tried to evaluate whether constant folding will reduce the total
memory size, so if there was more than 1 user, it should not be counted, as the
operand will remain. But with the current code it makes no sense at all.
