Add target_compatible_with from kwargs to build_script_kwargs

[daivinhtran]

The top-level _build_script_run target should also have target_compatible_with in order to work with platforms compatibility.

[UebelAndre]

The way args are passed here seems backward to me. I think target folks think about when defining cargo_build_script targets is actually _build_script_run. Thus we should default to passing all args to that and set the rust_binary target to manual. You can then constrain the target with both target_compatible_with which I feel most applies to running the script where exec_compatible_with would apply to compiling the script as the script is in cfg = "exec". How do you feel about passing kwargs to _build_script_run instead?

cc @scentini

[daivinhtran]

@UebelAndre Yes that's an approach I would prefer. Passing kwargs to _build_script_run make sense.

PTAL: 3385c97

I also introduced edition,srcs, crate_name, crate_root, and proc_macro_deps attributes to cargo_build_script macro so they can be passed to rust_binary to build. This ensures that all arguments to rust_binary is fully defined at the macro signature.

[UebelAndre]

Seems good to me! I’ll give @scentini a chance to look since I think they have some more nuanced uses with “compatible_with”.