diamonds: incompatible error due to cls class in default package fixed - cls file doesn't process declarations! = need to switch to mirror (IDEA-121866)

(cherry picked from commit 94d5c96730900e0f21cc3bd48143f2dea4411ae6)

java/java-tests/testData/codeInsight/clsHighlighting/IDEA121866.java

@@ -0,0 +1,5 @@
+class IDEA121866  {
+  {
+    A<String> a = new A<>();
+  }
+}