✅ IL for function vs expression-bodied-function

Why do these two compile to different things?

class Program {
    int Double1(int n) => n + n;

    int Double2(int n) {
        return n + n;
    }
}

class Program {
    int Double1(int n) => n + n;

    int Double2(int n) {
        return n + n;
    }
}