Merge boxWithStdlib testData into box, delete BoxWithStdlib test

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

@@ -0,0 +1,17 @@
+// WITH_REFLECT
+
+fun box(): String {
+    val l: Any = {}
+
+    val javaClass = l.javaClass
+    val enclosingMethod = javaClass.getEnclosingMethod()
+    if (enclosingMethod?.getName() != "box") return "method: $enclosingMethod"
+
+    val enclosingClass = javaClass.getEnclosingClass()!!.getName()
+    if (enclosingClass != "LambdaInFunctionKt") return "enclosing class: $enclosingClass"
+
+    val declaringClass = javaClass.getDeclaringClass()
+    if (declaringClass != null) return "anonymous function has a declaring class: $declaringClass"
+
+    return "OK"
+}