Build fails due to bindgen being unable to find Windows include directories about cargo-xwin

[messense]

Maybe we can pass sysroot to bindgen automatically, see https://github.com/rust-lang/rust-bindgen#environment-variables, do you want to give it a try?

[justtryingthingsout]

$ export BINDGEN_EXTRA_CLANG_ARGS_x86_64_pc_windows_msvc='--sysroot="/Users/plx/Library/Caches/cargo-xwin/xwin/sdk/"'
$ cargo xwin build --release --target x86_64-pc-windows-msvc
...
  exit status: 0
  cargo:rustc-link-lib=static=lzvn
  cargo:rustc-link-search=native=/Users/plx/Documents/Github/sepsplit-rs/target/x86_64-pc-windows-msvc/release/build/sepsplit-rs-hash/out
  cargo:rerun-if-changed=wrapper.h

  --- stderr
  ./src/ext/lzvn/FastCompression.h:8:10: fatal error: 'stdlib.h' file not found
  thread 'main' panicked at 'Unable to generate bindings: ClangDiagnostic("./src/ext/lzvn/FastCompression.h:8:10: fatal error: 'stdlib.h' file not found\n")', build.rs:35:10
  note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

it seems as though it can't find the proper headers even when passing in the SDK sysroot, would it perhaps require the include directories to be passed manually?

[justtryingthingsout]

Specifying the arguments as

BINDGEN_EXTRA_CLANG_ARGS_x86_64_pc_windows_msvc='-I/Users/plx/Library/Caches/cargo-xwin/xwin/crt/include -I/Users/plx/Library/Caches/cargo-xwin/xwin/sdk/include/ucrt -I/Users/plx/Library/Caches/cargo-xwin/xwin/sdk/include/um -I/Users/plx/Library/Caches/cargo-xwin/xwin/sdk/include/shared'

seems to make it work.

[messense]

Do you want to send a PR to add BINDGEN_EXTRA_CLANG_ARGS?