`@SuppressWarnings("all")` should suppress all warnings/hints

[anthonyvdotbe]

Consider the example from #533:

import java.io.IOException;

@SuppressWarnings("all")
class Foo {
    public static void main(String... args) {
        var _ = bar(IOException.class, () -> {});
        var _ = bar(String.class, () -> {});
    }

    static <T> T bar(Class<T> foo, Runnable bar) {
        return null;
    }
}

Actual: bar(IOException.class, () -> {}); gives a hint Throwable method result is ignored
Expected: no hints are shown, since I specified @SuppressWarnings("all")