When by enum:

Generate TABLESWITCH/LOOKUPSWITCH bytecode command in case of "when" by enum entries

compiler/testData/codegen/bytecodeText/whenEnumOptimization/bigEnum.kt

@@ -0,0 +1,26 @@
+import kotlin.test.assertEquals
+
+enum class BigEnum {
+    ITEM1 ITEM2 ITEM3 ITEM4 ITEM5 ITEM6 ITEM7 ITEM8 ITEM9 ITEM10 ITEM11 ITEM12 ITEM13 ITEM14 ITEM15 ITEM16 ITEM17 ITEM18 ITEM19 ITEM20
+}
+
+fun bar1(x : BigEnum) : String {
+    when (x) {
+        BigEnum.ITEM1, BigEnum.ITEM2, BigEnum.ITEM3 -> return "123"
+        BigEnum.ITEM4, BigEnum.ITEM5, BigEnum.ITEM6 -> return "456"
+    }
+
+    return "-1";
+
+}
+
+fun bar2(x : BigEnum) : String {
+    when (x) {
+        BigEnum.ITEM7, BigEnum.ITEM8, BigEnum.ITEM9 -> return "789"
+        BigEnum.ITEM10 -> return "10"
+        BigEnum.ITEM11, BigEnum.ITEM12 -> return "1112"
+        else -> return "-1"
+    }
+}
+
+// 2 TABLESWITCH