fix(cmake/Modules/CheckLuaNewstate.cc): compilation problem on cygwin
fix(cmake/Modules/CheckLuaNewstate.cc): compilation problem on cygwin

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

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