Add codegen box test templates for identifiers

compiler/tests-spec/testData/codegen/box/templates/identifiers/companionObject.kt

@@ -0,0 +1,22 @@
+<!DIRECTIVES("HELPERS: REFLECT")!>
+
+package org.jetbrains.<!ELEMENT(1)!>
+
+open class A {
+    companion object <!ELEMENT(2)!> {
+
+    }
+}
+
+class B {
+    companion object <!ELEMENT(3)!>: A() {
+
+    }
+}
+
+fun box(): String? {
+    if (!checkCompanionObjectName(A::class, "org.jetbrains.<!ELEMENT_VALIDATION(1)!>.A.<!ELEMENT_VALIDATION(2)!>")) return null
+    if (!checkCompanionObjectName(B::class, "org.jetbrains.<!ELEMENT_VALIDATION(1)!>.B.<!ELEMENT_VALIDATION(3)!>")) return null
+
+    return "OK"
+}