JVM: ensure the $ENTRIES field is initialized before use

#KT-57784 Fixed

compiler/testData/codegen/box/enum/enumEntriesInCompanion.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +EnumEntries
+// IGNORE_BACKEND: JVM, JS
+// WITH_STDLIB
+
+enum class MyEnum {
+    OK, NOPE;
+
+    companion object {
+        @OptIn(ExperimentalStdlibApi::class)
+        val ok = entries[0]
+    }
+}
+
+fun box(): String {
+    return MyEnum.ok.toString()
+}