Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/external/jvmStaticExternalPrivate.kt

@@ -0,0 +1,24 @@
+// WITH_RUNTIME
+// FULL_JDK
+
+class C {
+    companion object {
+        private @JvmStatic external fun foo()
+    }
+
+    fun bar() {
+        foo()
+    }
+}
+
+fun box(): String {
+    try {
+        C().bar()
+        return "Link error expected"
+    }
+    catch (e: java.lang.UnsatisfiedLinkError) {
+        if (e.message != "C.foo()V") return "Fail 1: " + e.message
+    }
+
+    return "OK"
+}