backend/tests: Add blackbox tests from Kotlin JVM

Added tests from testData/codegen/box directory. There are blackbox tests
in other directories and they are to be added.

backend.native/tests/external/codegen/blackbox/reflection/lambdaClasses/parameterNamesAndNullability.kt

@@ -0,0 +1,48 @@
+// TODO: muted automatically, investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// WITH_REFLECT
+
+import kotlin.reflect.*
+import kotlin.reflect.jvm.*
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+fun lambda() {
+    val f = { x: Int, y: String? -> }
+
+    val g = f.reflect()!!
+
+    // TODO: maybe change this name
+    assertEquals("<anonymous>", g.name)
+    assertEquals(listOf("x", "y"), g.parameters.map { it.name })
+    assertEquals(listOf(false, true), g.parameters.map { it.type.isMarkedNullable })
+}
+
+fun funExpr() {
+    val f = fun(x: Int, y: String?) {}
+
+    val g = f.reflect()!!
+
+    // TODO: maybe change this name
+    assertEquals("<no name provided>", g.name)
+    assertEquals(listOf("x", "y"), g.parameters.map { it.name })
+    assertEquals(listOf(false, true), g.parameters.map { it.type.isMarkedNullable })
+}
+
+fun extensionFunExpr() {
+    val f = fun String.(): String = this
+
+    val g = f.reflect()!!
+
+    assertEquals(KParameter.Kind.EXTENSION_RECEIVER, g.parameters.single().kind)
+    assertEquals(null, g.parameters.single().name)
+}
+
+fun box(): String {
+    lambda()
+    funExpr()
+    extensionFunExpr()
+
+    return "OK"
+}