Fixed test data for new lambda syntax

compiler/testData/diagnostics/tests/labels/kt361.kt

@@ -1,5 +1,5 @@
 fun nonlocals(b : Boolean) {
-    @a<!UNUSED_FUNCTION_LITERAL!>{(): Int ->
+    @a<!UNUSED_FUNCTION_LITERAL!>{
         fun foo() {
             if (b) {
                 <!RETURN_NOT_ALLOWED!>return@a 1<!> // The label must be resolved, but an error should be reported for a non-local return

compiler/testData/diagnostics/tests/labels/kt3920.kt

@@ -2,7 +2,7 @@
 //KT-3920 Labeling information is lost when passing through some expressions
 
 fun test() {
-    run @f{ (): Int ->
+    run @f{
         val x = if (1 > 2) return@f 1 else 2
         2
     }

compiler/testData/diagnostics/tests/labels/kt4603.kt

@@ -2,7 +2,7 @@
 //KT-4603 Labeling information is lost when passing through local classes or objects
 
 fun foo() {
-    val s = @l{ Int.() ->
+    val s: Int.() -> Unit = @l{
         class Local(val y: Int = this@l) {
             fun bar() {
                 val x: Int = this@l //unresolved

compiler/testData/diagnostics/tests/labels/kt591.kt

@@ -1,9 +1,9 @@
 //KT-591 Unresolved label in valid code
 
 fun test() {
-    val <!UNUSED_VARIABLE!>a<!> = @a{(Int?).() ->
+    val <!UNUSED_VARIABLE!>a<!>: (Int?).() -> Unit = @a{
         if (this != null) {
-            val <!UNUSED_VARIABLE!>b<!> = {String.() ->
+            val <!UNUSED_VARIABLE!>b<!>: String.() -> Unit = {
                 <!DEBUG_INFO_SMARTCAST!>this@a<!>.times(5) // @a Unresolved
             }
         }