Private visibility for non-const, non-jvmField class companion property backing field

Original commit: e116cc3206

jps/jps-plugin/testData/incremental/withJava/kotlinUsedInJava/jvmFieldChanged/const.kt.new

@@ -0,0 +1,9 @@
+package test
+
+class Klass {
+    companion object {
+        // Old and new constant values are different, but their hashes are the same
+        @JvmField
+        val CONST = "Ae"
+    }
+}