feat(library/simplifier): add support for simplifying even when heq module is not available
feat(library/simplifier): add support for simplifying even when heq module is not available

Signed-off-by: Leonardo de Moura <7610bae85f2b530654cc716772f1fe653373e892@microsoft.com>

leanprover/lean,Kha/lean,soonhokong/travis_test,avigad/lean,leanprover-community/lean,leanprover-community/lean,levnach/lean,soonhokong/lean-osx,leodemoura/lean,soonhokong/travis_test,UlrikBuchholtz/lean,dselsam/lean,soonhokong/travis_test,levnach/lean,digama0/lean,UlrikBuchholtz/lean,rlewis1988/lean,avigad/lean,codyroux/lean0.1,sp3ctum/lean,fpvandoorn/lean,soonhokong/lean-osx,codyroux/lean0.1,johoelzl/lean,c-cube/lean,soonhokong/lean-windows,soonhokong/lean,UlrikBuchholtz/lean,avigad/lean,dselsam/lean,levnach/lean,johoelzl/lean,leanprover-community/lean,avigad/lean,c-cube/lean,sp3ctum/lean,levnach/lean,javra/lean,rlewis1988/lean,johoelzl/lean,sp3ctum/lean,soonhokong/lean-osx,javra/lean,leodemoura/lean,fgdorais/lean,eigengrau/lean,dselsam/lean,UlrikBuchholtz/lean,fgdorais/lean,digama0/lean,fpvandoorn/lean2,digama0/lean,fpvandoorn/lean,soonhokong/lean,UlrikBuchholtz/lean,rlewis1988/lean,digama0/lean,fpvandoorn/lean2,rlewis1988/lean,fpvandoorn/lean,codyroux/lean0.1,dselsam/lean,levnach/lean,eigengrau/lean,htzh/lean,javra/lean,digama0/lean,Kha/lean,dselsam/lean,htzh/lean,Kha/lean,sp3ctum/lean,javra/lean,fgdorais/lean,fpvandoorn/lean2,codyroux/lean0.1,Kha/lean,fgdorais/lean,htzh/lean,soonhokong/travis_test,leanprover/lean,leanprover/lean,c-cube/lean,leanprover-community/lean,fpvandoorn/lean,Kha/lean,htzh/lean,digama0/lean,soonhokong/lean-windows,leanprover-community/lean,sp3ctum/lean,soonhokong/lean-windows,leodemoura/lean,leanprover-community/lean,fgdorais/lean,c-cube/lean,leodemoura/lean,johoelzl/lean,soonhokong/lean-windows,eigengrau/lean,rlewis1988/lean,leanprover/lean,leanprover/lean,soonhokong/lean,dselsam/lean,fgdorais/lean,fpvandoorn/lean,johoelzl/lean,c-cube/lean,soonhokong/lean-osx,eigengrau/lean,fpvandoorn/lean2,soonhokong/lean-osx,johoelzl/lean,Kha/lean,avigad/lean,leodemoura/lean,soonhokong/lean,eigengrau/lean,soonhokong/lean,fpvandoorn/lean2,javra/lean,htzh/lean,fpvandoorn/lean,rlewis1988/lean,leanprover/lean,avigad/lean,leodemoura/lean,soonhokong/lean-windows