Adjust testData to new labels syntax

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

@@ -5,8 +5,8 @@ public inline fun <reified T> Array(n: Int, block: (Int) -> T): Array<T> = null!
 
 fun test() {
     val ints = Array<Int?>(2, { null })
-    ints.forEach @lit {
-        if (it == null) return @lit
+    ints.forEach lit@ {
+        if (it == null) return@lit
         use(<!DEBUG_INFO_SMARTCAST!>it<!> + 5)
     }
 }

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

@@ -1,5 +1,5 @@
 fun nonlocals(b : Boolean) {
-    @a<!UNUSED_FUNCTION_LITERAL!>{
+    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{
+    run f@{
         val x = if (1 > 2) return@f 1 else 2
         2
     }

compiler/testData/diagnostics/tests/labels/kt4586.kt

@@ -7,7 +7,7 @@ fun string(init: StringBuilder.() -> Unit): String{
     return answer.toString()
 }
 
-val str = string @l{
+val str = string l@{
     append("hello, ")
 
     val sub = string {

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: Int.() -> Unit = @l{
+    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

@@ -1,10 +1,10 @@
 //KT-591 Unresolved label in valid code
 
 fun test() {
-    val <!UNUSED_VARIABLE!>a<!>: (Int?).() -> Unit = @a{
+    val <!UNUSED_VARIABLE!>a<!>: (Int?).() -> Unit = a@{
         if (this != null) {
             val <!UNUSED_VARIABLE!>b<!>: String.() -> Unit = {
-                <!DEBUG_INFO_SMARTCAST!>this@a<!>.times(5) // @a Unresolved
+                <!DEBUG_INFO_SMARTCAST!>this@a<!>.times(5) // a@ Unresolved
             }
         }
     }

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

@@ -15,7 +15,7 @@ fun B.b() {
 }
 
 fun test() {
-    @b <!UNUSED_FUNCTION_LITERAL!>{ <!DEPRECATED_LAMBDA_SYNTAX!>B.()<!> ->
+    b@ <!UNUSED_FUNCTION_LITERAL!>{ <!DEPRECATED_LAMBDA_SYNTAX!>B.()<!> ->
         object : A {
             override fun foo() {
                 this@b.bar()