ensure language level is retrieved from analyzed method when method hierarchy is processed

java/java-tests/testData/codeInsight/multipleJdks/java3/p/LanguageLevelInReturnTypeCheck.java

@@ -0,0 +1,3 @@
+package p;
+
+class C extends B {}

java/java-tests/testData/codeInsight/multipleJdks/java7/p/LanguageLevelInReturnTypeCheck.java

@@ -0,0 +1,9 @@
+package p;
+
+public class B extends A {
+  protected java.util.List<String> get() {return null;}
+}
+
+class A {
+  protected java.util.List<String> get() {return null;}
+}