Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/reflection/enclosing/lambdaInPackage.kt

@@ -0,0 +1,19 @@
+// WITH_REFLECT
+
+val l: Any = {}
+
+fun box(): String {
+    val enclosingClass = l.javaClass.getEnclosingClass()!!.getName()
+    if (enclosingClass != "LambdaInPackageKt") return "enclosing class: $enclosingClass"
+
+    val enclosingConstructor = l.javaClass.getEnclosingConstructor()
+    if (enclosingConstructor != null) return "enclosing constructor found: $enclosingConstructor"
+
+    val enclosingMethod = l.javaClass.getEnclosingMethod()
+    if (enclosingMethod != null) return "enclosing method found: $enclosingMethod"
+
+    val declaringClass = l.javaClass.getDeclaringClass()
+    if (declaringClass != null) return "anonymous function has a declaring class: $declaringClass"
+
+    return "OK"
+}