Run multiple checker at the same time if error issues

[Ao-senXiong]

For this example below, ./checker/bin/javac -processor nullness,regex Demo.java only output

Demo.java:6: error: [dereference.of.nullable] dereference of possibly-null reference o
        o.toString();
        ^
1 error

import org.checkerframework.checker.nullness.qual.Nullable;
import java.util.regex.Pattern;

class Demo {
    void test(@Nullable Object o) {
        o.toString();
	    Pattern.compile("x(");
    }
}

Think about how to run multiple checker at the same time when each checker issue errors