Fix for KT-7999: Wrong result when use nullable types as reified parameter, KT-8043: Unsafe cast to reified parameter throws NPE instead of TypeCastException

#KT-7999 Fixed
  #KT-8043 Fixed

~

compiler/testData/codegen/boxWithJava/reified/isCheck/JavaClass.java

@@ -0,0 +1,11 @@
+public class JavaClass {
+
+    public static String nullString() {
+        return null;
+    }
+
+    public static String nonnullString() {
+        return "OK";
+    }
+
+}