add test for short-circuit AND and OR assignment
add test for short-circuit AND and OR assignment

closes #31

raulgrell/zig,Dimenus/zig,zig-lang/zig,andrewrk/zig,Dimenus/zig,Dimenus/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig,raulgrell/zig,zig-lang/zig,andrewrk/zig,raulgrell/zig