Fix spaces in labeled expression (KT-14131)

https://github.com/JetBrains/kotlin/pull/978

(cherry picked from commit fdd5ba7)

idea/testData/formatter/LabeledExpression.kt

@@ -0,0 +1,40 @@
+fun test1() {
+    loop@    while(true) {
+
+    }
+}
+
+fun test2() {
+    listOf(1).forEach lit@    {
+        if (it == 0) return@lit
+        print(it)
+    }
+}
+
+fun test3() {
+    l1@
+
+
+    /*comment*/ {
+
+    }
+
+    l2@    /*comment*/ {
+
+    }
+}
+
+fun test4() {
+    l1@
+
+
+    //eol comment
+    {
+
+    }
+
+    l2@    //eol comment
+    {
+
+    }
+}