Given that names of parameters are lost during compilation, how does Spring autowire by parameter name?

Consider following configuration with two beans of the same type created:

@Configuration
@ComponentScan(basePackageClasses = TwoStrings.class)
public class Config {

    @Bean
    public String one() {
        return "one";
    }

    @Bean
    public String two() {
        return "two";
    }

}

Another bean that depends on the two beans above is created by component scan:

@Component
public class TwoStrings {

    public final String a;
    public final String b;

    @Autowired
    public TwoStrings(String one, String two) {
        this.a = one;
        this.b = two;
    }

}

The names of local variables/parameters are lost during compilation and are not available at runtime:

However, Spring somehow autowires two String beans correctly. The example test below

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = Config.class )
public class Example {

    @Autowired
    private TwoStrings twoStrings;

    @Test
    public void test() {
        System.out.println(twoStrings.a);
        System.out.println(twoStrings.b);
    }

}

prints

one
two

Given the name of constructor parameters are lost, I would expect Spring to throw the exception saying that there is more than 1 bean of type String, however Spring somehow autowires beans using parameters names.

The question is how Spring knows the names of constructor parameters?