FIR: fix label stealling and crash with multiple labels

Consider the code below

```
fun test() {
  a@ b@ {
    {}
  }
}
```

Currently when the code is converted to FIR, label `b` is bound to the
outer lambda and `a` gets bound to the inner lambda because it's not
consumed. This is wrong and also leads transfromation to fail with
exceptions because of the unexpected consumption of `a`.

This change fixes the above issue by designating a specific node in the
AST as the allowed user of a label when the label is added.

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -6271,6 +6271,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/controlStructures/localReturnInsidePropertyAccessor.kt");
             }
 
+            @Test
+            @TestMetadata("nestedLoopsWithMultipleLabels.kt")
+            public void testNestedLoopsWithMultipleLabels() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/controlStructures/nestedLoopsWithMultipleLabels.kt");
+            }
+
             @Test
             @TestMetadata("notAFunctionLabel_after.kt")
             public void testNotAFunctionLabel_after() throws Exception {