[Spec tests] Add spec tests for kotlin.Nothing, kotlin.Unit, reference equality and cast expressions

compiler/tests-spec/testData/codegen/box/linked/expressions/cast-expression/p-1/pos/1.1.kt

@@ -0,0 +1,30 @@
+// WITH_RUNTIME
+
+/*
+ * KOTLIN CODEGEN BOX SPEC TEST (POSITIVE)
+ *
+ * SPEC VERSION: 0.1-213
+ * PLACE: expressions, cast-expression -> paragraph 1 -> sentence 1
+ * NUMBER: 1
+ * DESCRIPTION: check of the cast operators as or as?
+ */
+
+fun box(): String {
+    val c = Class()
+    if (c.data !is () -> Nothing) return "NOK"
+    val e1 : () -> Nothing = c.exception as () -> Nothing as? () -> Nothing ?: return "NOK"
+    val v = c.value as () -> Nothing as? () -> Nothing ?: return "NOK"
+
+    return "OK"
+}
+
+open class Class() {
+    var data: () -> Nothing = { throwException("boo") as Nothing }
+    var exception: () -> CharSequence = { throwException("foo") as String }
+    val value: () -> Any
+        get() = { TODO() as Nothing }
+}
+
+private fun throwException(m: String): Any {
+    throw  IllegalArgumentException(m)
+}

compiler/tests-spec/testData/codegen/box/linked/expressions/cast-expression/testsMap.json

@@ -0,0 +1,14 @@
+{
+  "1": {
+    "pos": {
+      "1": [
+        {
+          "specVersion": "0.1-213",
+          "casesNumber": 0,
+          "description": " check of the cast operators as or as?",
+          "unexpectedBehaviour": false
+        }
+      ]
+    }
+  }
+}