message: feat(c-api) Expand macros of the crate when generating C bindings.
diff: @@ -61,6 +61,10 @@ macro_rules! map_feature_as_c_define {
  }
  fn main() {
  + if ::std::env::var("_CBINDGEN_IS_RUNNING").is_ok() {
  + return;
  + }
  +
  let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
  let out_dir = env::var("OUT_DIR").unwrap();
  @@ -285,6 +289,12 @@ fn new_builder(language: Language, crate_dir: &str, include_guard: &str, header:
  .with_include_guard(include_guard)
  .with_header(header)
  .with_documentation(false)
  + .with_parse_expand(&[env::var("CARGO_PKG_NAME").unwrap()])
  + .with_parse_expand_features(if env::var("CARGO_FEATURE_SYSTEM_LIBFFI").is_ok() {
  + &["system-libffi"]
  + } else {
  + &[]
  + })
  .with_define("target_family", "windows", "_WIN32")
  .with_define("target_arch", "x86_64", "ARCH_X86_64")
  .with_define("feature", "jit", JIT_FEATURE_AS_C_DEFINE)
  