ECJ is too clever while infering generic types with Exceptions

The following class compiles and the test runs fine inside Eclipse but does not compile with `javac`. While I like that `ecj` can perfectly understand my intension, it seems to be inferring too much, as the code would not compile elsewhere.

```java
import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
import static org.junit.jupiter.api.Assertions.assertThrowsExactly;

import java.io.IOException;
import java.util.function.Supplier;

import org.junit.jupiter.api.Test;

public class MinimalTest {

public T supply(Supplier supplier) {
return supplier.get();
}

public @FunctionalInterface interface BadSupplier1 {
T get() throws X1;
}

public T supply(Class x1, BadSupplier1 supplier) throws X1 {
return supplier.get();
}

public @FunctionalInterface interface BadSupplier2 {
T get() throws X1, X2;
}

public T supply(Class x1, Class x2, BadSupplier2 supplier) throws X1, X2 {
return supplier.get();
}

public @Test void test() {
assertDoesNotThrow(() -> supply(() -> null));
assertThrowsExactly(IOException.class, () -> supply(IOException.class, () -> {
throw new IOException("To be expected");
}));
assertThrowsExactly(ClassNotFoundException.class, () -> supply(ClassNotFoundException.class, () -> {
throw new ClassNotFoundException("To be expected");
}));
assertThrowsExactly(IOException.class, () -> supply(IOException.class, IOException.class, () -> {
throw new IOException("To be expected");
}));
assertThrowsExactly(ClassNotFoundException.class, () -> supply(ClassNotFoundException.class, ClassNotFoundException.class, () -> {
throw new ClassNotFoundException("To be expected");
}));
// BREAKS ON NEXT LINE in javac but compiles and runs fine with ecj
assertThrowsExactly(IOException.class, () -> supply(IOException.class, ClassNotFoundException.class, () -> {
throw new IOException("To be expected");
}));
}
}
```