Add integration test for lib injection

tests/mybin/Cargo.lock

@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "mybin"
+version = "0.1.0"
+dependencies = [
+ "mylib",
+]
+
+[[package]]
+name = "mylib"
+version = "0.1.0"

tests/mybin/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "mybin"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+mylib = { path = "../mylib" }

tests/mybin/src/main.rs

@@ -0,0 +1,12 @@
+#[link(name = "mylib", kind = "dylib")]
+extern {
+	fn mylib_foo() -> u8;
+	fn mylib_bar() -> u8;
+}
+
+fn main() {
+	println!("Hello, world!");
+
+	assert_eq!(unsafe { mylib_bar() }, 100);
+	std::process::exit(unsafe { mylib_foo() } as i32);
+}