Make exprIsConApp_maybe use MCoercion
In exprIsConApp_maybe
we have
data ConCont = CC [CoreExpr] Coercion
But the Coercion
is almost always Refl. We have MCoercion
for this exact purpose.
Idea: just replace Coercion
by MCoercion
. Simpler, more direct, and perhaps a tiny bit more efficient.