Add cleaned up compiler design document
Add cleaned up compiler design document

The document is based on early design notes for Duktape 1.0 and is not
entirely up-to-date or very clean, but it still provides a reasonable
overview of how the compiler works.

svaarala/duktape,tassmjau/duktape,tassmjau/duktape,jmptrader/duktape,zeropool/duktape,reqshark/duktape,sloth4413/duktape,svaarala/duktape,markand/duktape,jmptrader/duktape,markand/duktape,chenyaqiuqiu/duktape,tassmjau/duktape,sloth4413/duktape,harold-b/duktape,chenyaqiuqiu/duktape,markand/duktape,svaarala/duktape,tassmjau/duktape,nivertech/duktape,zeropool/duktape,kphillisjr/duktape,kphillisjr/duktape,reqshark/duktape,harold-b/duktape,zeropool/duktape,jmptrader/duktape,sloth4413/duktape,reqshark/duktape,harold-b/duktape,markand/duktape,jmptrader/duktape,kphillisjr/duktape,markand/duktape,markand/duktape,reqshark/duktape,tassmjau/duktape,chenyaqiuqiu/duktape,sloth4413/duktape,chenyaqiuqiu/duktape,reqshark/duktape,nivertech/duktape,sloth4413/duktape,chenyaqiuqiu/duktape,chenyaqiuqiu/duktape,svaarala/duktape,zeropool/duktape,zeropool/duktape,reqshark/duktape,jmptrader/duktape,sloth4413/duktape,nivertech/duktape,svaarala/duktape,harold-b/duktape,zeropool/duktape,nivertech/duktape,harold-b/duktape,tassmjau/duktape,kphillisjr/duktape,nivertech/duktape,zeropool/duktape,zeropool/duktape,markand/duktape,reqshark/duktape,kphillisjr/duktape,harold-b/duktape,kphillisjr/duktape,chenyaqiuqiu/duktape,markand/duktape,jmptrader/duktape,tassmjau/duktape,kphillisjr/duktape,tassmjau/duktape,nivertech/duktape,chenyaqiuqiu/duktape,tassmjau/duktape,svaarala/duktape,markand/duktape,zeropool/duktape,svaarala/duktape,reqshark/duktape,nivertech/duktape,kphillisjr/duktape,svaarala/duktape,reqshark/duktape,chenyaqiuqiu/duktape,kphillisjr/duktape,harold-b/duktape,jmptrader/duktape,reqshark/duktape,svaarala/duktape,sloth4413/duktape,chenyaqiuqiu/duktape,harold-b/duktape,kphillisjr/duktape,tassmjau/duktape,harold-b/duktape,zeropool/duktape,jmptrader/duktape,nivertech/duktape,sloth4413/duktape,harold-b/duktape,sloth4413/duktape,markand/duktape,jmptrader/duktape,jmptrader/duktape,sloth4413/duktape,nivertech/duktape,nivertech/duktape