dfa: don't merge by type states which have different eq states

java/java-tests/testData/inspection/dataFlow/fixture/DontForgetEqInfoWhenMergingByType.java

@@ -0,0 +1,21 @@
+class Some {
+
+  private boolean canBePatternVariable(PsiElement element) {
+    if (element instanceof LeafElement) {
+      return true;
+    }
+
+    while (!(element instanceof LeafElement) && element != null) {
+      element = getNextObject(element);
+    }
+    return element != null;
+  }
+
+  PsiElement getNextObject(PsiElement element) { return element; }
+  
+  class LeafElement {}
+  interface PsiElement {}
+
+}
+
+