Move some tests from boxWithStdlib/ to box/

Move those tests which do not require neither stdlib nor reflect

compiler/testData/codegen/box/callableReference/function/extensionFromTopLevelUnitOneStringArg.kt

@@ -0,0 +1,14 @@
+class A {
+    var result = "Fail"
+}
+
+fun A.foo(newResult: String) {
+    result = newResult
+}
+
+fun box(): String {
+    val a = A()
+    val x = A::foo
+    x(a, "OK")
+    return a.result
+}