Bug 195757 - Missing redundant null check in if condition through ternary operator

From https://bugs.eclipse.org/bugs/show_bug.cgi?id=195757

```java
public class X {

boolean test() {
return true;
}

int foo() {
if ((test() ? null : null) == null)
return 1;
return 0;
}

// more complex

int bar() {
String s = null;
if ((test() ? s : null) == null)
return 1;
return 0;
}
}
```
In both case, a "redundant null check" should be reported.

For initial discussion see bugzilla.