They are not really ignored. Syntax should still be valid when not compiling as an effect.
Well, yes, the syntax needs to be valid, but the point is that we shouldn't emit a fixme just because the technique is declared. I.e. if we remove this fixme, then we correctly compile more HLSL shaders than we previously had done. On the other hand, you can have an fx_4_0 effect without any techniques, and we don't even implement writing that. Hence we probably need a hlsl_fixme() for that. We probably also want an hlsl_fixme() for techniques that's gated to only apply to effects targets.