add selftest for two's complement arithmetic
add selftest for two's complement arithmetic

pombredanne/duktape,pombredanne/duktape,skomski/duktape,haosu1987/duktape,nivertech/duktape,harold-b/duktape,nivertech/duktape,daimajia/duktape,markand/duktape,tassmjau/duktape,markand/duktape,reqshark/duktape,kphillisjr/duktape,thurday/duktape,pombredanne/duktape,tassmjau/duktape,zeropool/duktape,zeropool/duktape,jmptrader/duktape,jmptrader/duktape,harold-b/duktape,skomski/duktape,svaarala/duktape,skomski/duktape,svaarala/duktape,tassmjau/duktape,tassmjau/duktape,kphillisjr/duktape,svaarala/duktape,harold-b/duktape,markand/duktape,haosu1987/duktape,chenyaqiuqiu/duktape,zeropool/duktape,rwaldron/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,pombredanne/duktape,markand/duktape,thurday/duktape,harold-b/duktape,jmptrader/duktape,sloth4413/duktape,svaarala/duktape,daimajia/duktape,chenyaqiuqiu/duktape,tassmjau/duktape,reqshark/duktape,jmptrader/duktape,sloth4413/duktape,pombredanne/duktape,pombredanne/duktape,svaarala/duktape,tassmjau/duktape,markand/duktape,nivertech/duktape,haosu1987/duktape,zeropool/duktape,thurday/duktape,rwaldron/duktape,chenyaqiuqiu/duktape,nivertech/duktape,sloth4413/duktape,reqshark/duktape,reqshark/duktape,daimajia/duktape,sloth4413/duktape,rwaldron/duktape,tassmjau/duktape,rwaldron/duktape,haosu1987/duktape,haosu1987/duktape,sloth4413/duktape,thurday/duktape,eddieh/duktape,reqshark/duktape,svaarala/duktape,kphillisjr/duktape,pombredanne/duktape,nivertech/duktape,harold-b/duktape,thurday/duktape,harold-b/duktape,markand/duktape,skomski/duktape,kphillisjr/duktape,eddieh/duktape,zeropool/duktape,jmptrader/duktape,tassmjau/duktape,kphillisjr/duktape,chenyaqiuqiu/duktape,haosu1987/duktape,eddieh/duktape,thurday/duktape,skomski/duktape,nivertech/duktape,haosu1987/duktape,thurday/duktape,skomski/duktape,kphillisjr/duktape,nivertech/duktape,svaarala/duktape,kphillisjr/duktape,harold-b/duktape,svaarala/duktape,chenyaqiuqiu/duktape,skomski/duktape,jmptrader/duktape,eddieh/duktape,jmptrader/duktape,jmptrader/duktape,svaarala/duktape,jmptrader/duktape,haosu1987/duktape,tassmjau/duktape,markand/duktape,jmptrader/duktape,daimajia/duktape,nivertech/duktape,zeropool/duktape,skomski/duktape,haosu1987/duktape,sloth4413/duktape,nivertech/duktape,kphillisjr/duktape,haosu1987/duktape,markand/duktape,reqshark/duktape,nivertech/duktape,reqshark/duktape,harold-b/duktape,sloth4413/duktape,eddieh/duktape,chenyaqiuqiu/duktape,sloth4413/duktape,zeropool/duktape,kphillisjr/duktape,zeropool/duktape,zeropool/duktape,chenyaqiuqiu/duktape,harold-b/duktape,rwaldron/duktape,chenyaqiuqiu/duktape,eddieh/duktape,reqshark/duktape,harold-b/duktape,eddieh/duktape,eddieh/duktape,markand/duktape,thurday/duktape,eddieh/duktape,sloth4413/duktape,thurday/duktape,reqshark/duktape,pombredanne/duktape,zeropool/duktape,eddieh/duktape,rwaldron/duktape,daimajia/duktape,pombredanne/duktape,kphillisjr/duktape,markand/duktape,sloth4413/duktape,daimajia/duktape,tassmjau/duktape,skomski/duktape,reqshark/duktape,pombredanne/duktape,skomski/duktape,thurday/duktape