RawFirBuilder: fix label bounding for binary operations

#KT-57880 Fixed

compiler/testData/diagnostics/tests/labels/labelToOuterLambda.fir.kt

@@ -1,13 +0,0 @@
-// ISSUE: KT-57880
-
-fun outerLambda(action: String.() -> Unit) {}
-var lambda: Int.() -> Unit = {}
-fun consume(arg: String) {}
-
-fun main() {
-    outerLambda {
-        lambda = {
-            consume(<!ARGUMENT_TYPE_MISMATCH!>this@outerLambda<!>)
-        }
-    }
-}

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

@@ -1,8 +1,10 @@
+// FIR_IDENTICAL
 // ISSUE: KT-57880
 
 fun outerLambda(action: String.() -> Unit) {}
 var lambda: Int.() -> Unit = {}
 fun consume(arg: String) {}
+fun consumeInt(arg: Int) {}
 
 fun main() {
     outerLambda {
@@ -10,4 +12,10 @@ fun main() {
             consume(this@outerLambda)
         }
     }
+
+    outerLambda {
+        lambda = innerLambda@{
+            consumeInt(this@innerLambda)
+        }
+    }
 }