Fix ClassCastException at FirUninitializedEnumChecker

compiler/testData/diagnostics/tests/controlFlowAnalysis/UninitializedEnumCompanionVals.fir.kt

@@ -0,0 +1,17 @@
+// SKIP_TXT
+
+enum class A(val z: Any) {
+    Y(<!UNINITIALIZED_VARIABLE!>x<!>);
+
+    companion object {
+        val x = A.Y.ordinal
+    }
+}
+
+enum class B(val z: Any) {
+    Y(<!UNINITIALIZED_VARIABLE!>B.x<!>);
+
+    companion object {
+        val x = B.Y.ordinal
+    }
+}

compiler/testData/diagnostics/tests/controlFlowAnalysis/UninitializedEnumCompanionVals.kt

@@ -0,0 +1,17 @@
+// SKIP_TXT
+
+enum class A(val z: Any) {
+    Y(<!UNINITIALIZED_VARIABLE!>x<!>);
+
+    companion object {
+        val x = A.Y.ordinal
+    }
+}
+
+enum class B(val z: Any) {
+    Y(B.x);
+
+    companion object {
+        val x = B.Y.ordinal
+    }
+}