stage2: astgen for if and while with optionals
stage2: astgen for if and while with optionals

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