[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/j+k/collectionOverrides/collectionStringImpl.fir.kt

@@ -0,0 +1,85 @@
+// FILE: CollectionStringImpl.java
+
+import java.util.Collection;
+import java.util.Iterator;
+
+public class CollectionStringImpl implements Collection<String> {
+    @Override
+    public int size() {
+        return 0;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return false;
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return false;
+    }
+
+
+    @Override
+    public Iterator<String> iterator() {
+        return null;
+    }
+
+
+    @Override
+    public Object[] toArray() {
+        return new Object[0];
+    }
+
+
+    @Override
+    public <T> T[] toArray(T[] a) {
+        return null;
+    }
+
+    @Override
+    public boolean add(String s) {
+        return false;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        return false;
+    }
+
+    @Override
+    public boolean containsAll(Collection<?> c) {
+        return false;
+    }
+
+    @Override
+    public boolean addAll(Collection<? extends String> c) {
+        return false;
+    }
+
+    @Override
+    public boolean removeAll(Collection<?> c) {
+        return false;
+    }
+
+    @Override
+    public boolean retainAll(Collection<?> c) {
+        return false;
+    }
+
+    @Override
+    public void clear() {
+
+    }
+
+    public boolean contains(String o) {
+        return true;
+    }
+}
+
+// FILE: main.kt
+
+fun test(x: CollectionStringImpl) {
+    x.contains("")
+    (x as Collection<String>).contains("")
+}