message: Remove ability to use object file engine with compiler from C API
  Due to the way object file engine works, it only makes sense to use in
  headless mode from the C API.
diff: @@ -141,14 +141,8 @@ cfg_if! {
  Box::new(wasm_engine_t { inner: engine })
  }
  }
  - else if #[cfg(all(feature = "object-file", feature = "compiler"))] {
  - #[no_mangle]
  - pub extern "C" fn wasm_engine_new() -> Box<wasm_engine_t> {
  - let mut compiler_config: Box<dyn CompilerConfig> = get_default_compiler_config();
  - let engine: Arc<dyn Engine + Send + Sync> = Arc::new(ObjectFile::new(&mut *compiler_config).engine());
  - Box::new(wasm_engine_t { inner: engine })
  - }
  - }
  + // There are currently no uses of the object-file engine + compiler from the C API.
  + // So if we get here, we default to headless mode regardless of if `compiler` is enabled.
  else if #[cfg(feature = "object-file")] {
  #[no_mangle]
  pub extern "C" fn wasm_engine_new() -> Box<wasm_engine_t> {
  @@ -227,8 +221,10 @@ pub extern "C" fn wasm_engine_new_with_config(
  },
  wasmer_engine_t::OBJECT_FILE => {
  cfg_if! {
  + // There are currently no uses of the object-file engine + compiler from the C API.
  + // So we run in headless mode.
  if #[cfg(feature = "object-file")] {
  - Arc::new(ObjectFile::new(&mut *compiler_config).engine())
  + Arc::new(ObjectFile::headless().engine())
  } else {
  return None;
  }
  