feat(library/kernel_bindings): improve Fun/Pi Lua APIs
feat(library/kernel_bindings): improve Fun/Pi Lua APIs

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

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