codegen: disable memoization, fix entity drvs
codegen: disable memoization, fix entity drvs

Disable memoization of constants, lvalues, and rvalues, since the
compiler has no way to otherwise enforce that a value always dominates
its uses. Also, memoizing rvalues has the nasty side effect of not
properly resampling a signal when needed, breaking event triggers.

Also increase the delay of entity temporary signal drives to 1e.

fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore,fabianschuiki/moore