Added tests on labels

#KT-1703 Fixed
 #KT-361 Fixed
 #KT-3920 Fixed
 #KT-3988 Fixed
 #KT-4247 Fixed
 #KT-4586 Fixed
 #KT-4603 Fixed
 #KT-591 Fixed

compiler/testData/diagnostics/tests/labels/kt1703.kt

@@ -0,0 +1,15 @@
+//KT-1703 Reference to label is unresolved
+
+fun test() {
+    val ints = Array<Int?>(2, { null })
+    ints.forEach @lit {
+        if (it == null) <!RETURN_NOT_ALLOWED_EXPLICIT_RETURN_TYPE_REQUIRED!>return @lit<!>
+        use(<!DEBUG_INFO_AUTOCAST!>it<!> + 5)
+    }
+}
+
+fun <T> Array<out T>.forEach(operation: (T) -> Unit) {
+    for (element in this) operation(element)
+}
+
+fun use(a: Any?) = a