Merge boxWithStdlib testData into box, delete BoxWithStdlib test

compiler/testData/codegen/box/reflection/mapping/functions.kt

@@ -0,0 +1,29 @@
+// WITH_REFLECT
+
+import kotlin.reflect.*
+import kotlin.reflect.jvm.*
+
+class K {
+    fun foo(s: String): Int = s.length
+}
+fun bar(s: String): Int = s.length
+fun String.baz(): Int = this.length
+
+fun check(f: KFunction<Int>) {
+    assert(f.javaConstructor == null) { "Fail f constructor" }
+    assert(f.javaMethod != null) { "Fail f method" }
+    val m = f.javaMethod!!
+
+    assert(m.kotlinFunction != null) { "Fail m function" }
+    val ff = m.kotlinFunction!!
+
+    assert(f == ff) { "Fail f != ff" }
+}
+
+fun box(): String {
+    check(K::foo)
+    check(::bar)
+    check(String::baz)
+
+    return "OK"
+}