fix: also check cfg gated field for bootloader dependency

Author: yusdacra

build.rs

@@ -242,7 +242,15 @@ mod binary {
 
                 if manifest
                     .get("dependencies")
-                    .and_then(|d| d.get("bootloader"))
+                    .and_then(|d| {
+                        d.get("bootloader").or_else(|| {
+                            manifest
+                                .get("target")
+                                .and_then(|table| table.get(r#"cfg(target_arch = "x86_64")"#))
+                                .and_then(|table| table.get("dependencies"))
+                                .and_then(|table| table.get("bootloader"))
+                        })
+                    })
                     .is_some()
                 {
                     // it seems to be the correct Cargo.toml