Constant fold choice expression if both sides eval to the same result.
check for min, max in greater/less than expressions.
c gen: allow ExpMaxMin expr to be used for min vals for unsigned types.
constant fold ExpMaxMin expressions.
const fold: factor out Haskell computations.
string: make exports explicit, fix toIx cast.
toIx: make toIx cast explicit.
constFold: recursively lift up conditional expressions.
Make toIx cast explicit.
more sharing in conditional lifting.
in compiler asserts, decompose large Boolean expressions.
ivory examples: helpful error message for clang test exec.