Some enum-related fixes

(NB: testEnumClass3 doesn't work yet, effective modality required for enum class)

compiler/testData/ir/irText/classes/enumWithSecondaryCtor.kt

@@ -1,5 +1,10 @@
 // WITH_RUNTIME
 
+enum class Test0(val x: Int) {
+    ZERO;
+    constructor() : this(0)
+}
+
 enum class Test1(val x: Int) {
     ZERO, ONE(1);
     constructor() : this(0)

compiler/testData/ir/irText/classes/enumWithSecondaryCtor.txt

@@ -1,4 +1,28 @@
 FILE /enumWithSecondaryCtor.kt
+  CLASS ENUM_CLASS Test0
+    CONSTRUCTOR private constructor Test0(x: kotlin.Int)
+      BLOCK_BODY
+        ENUM_CONSTRUCTOR_CALL 'constructor Enum(String, Int)'
+        INSTANCE_INITIALIZER_CALL classDescriptor='Test0'
+    PROPERTY public final val x: kotlin.Int
+      FIELD PROPERTY_BACKING_FIELD public final val x: kotlin.Int
+        EXPRESSION_BODY
+          GET_VAR 'value-parameter x: Int' type=kotlin.Int origin=INITIALIZE_PROPERTY_FROM_PARAMETER
+      FUN DEFAULT_PROPERTY_ACCESSOR public final fun <get-x>(): kotlin.Int
+        BLOCK_BODY
+          RETURN type=kotlin.Nothing from='<get-x>(): Int'
+            GET_FIELD 'x: Int' type=kotlin.Int origin=null
+              receiver: THIS of 'Test0' type=Test0
+    ENUM_ENTRY enum entry ZERO
+      init: ENUM_CONSTRUCTOR_CALL 'constructor Test0()'
+    CONSTRUCTOR private constructor Test0()
+      BLOCK_BODY
+        DELEGATING_CONSTRUCTOR_CALL 'constructor Test0(Int)'
+          x: CONST Int type=kotlin.Int value='0'
+    FUN ENUM_CLASS_SPECIAL_MEMBER public final fun values(): kotlin.Array<Test0>
+      SYNTHETIC_BODY kind=ENUM_VALUES
+    FUN ENUM_CLASS_SPECIAL_MEMBER public final fun valueOf(value: kotlin.String): Test0
+      SYNTHETIC_BODY kind=ENUM_VALUEOF
   CLASS ENUM_CLASS Test1
     CONSTRUCTOR private constructor Test1(x: kotlin.Int)
       BLOCK_BODY
@@ -14,7 +38,7 @@ FILE /enumWithSecondaryCtor.kt
             GET_FIELD 'x: Int' type=kotlin.Int origin=null
               receiver: THIS of 'Test1' type=Test1
     ENUM_ENTRY enum entry ZERO
-      init: ENUM_CONSTRUCTOR_CALL 'constructor Test1(Int)'
+      init: ENUM_CONSTRUCTOR_CALL 'constructor Test1()'
     ENUM_ENTRY enum entry ONE
       init: ENUM_CONSTRUCTOR_CALL 'constructor Test1(Int)'
         x: CONST Int type=kotlin.Int value='1'
@@ -45,7 +69,7 @@ FILE /enumWithSecondaryCtor.kt
       class: CLASS ENUM_ENTRY ZERO
         CONSTRUCTOR private constructor ZERO()
           BLOCK_BODY
-            ENUM_CONSTRUCTOR_CALL 'constructor Test2(Int)'
+            ENUM_CONSTRUCTOR_CALL 'constructor Test2()'
             INSTANCE_INITIALIZER_CALL classDescriptor='ZERO'
         FUN public open override fun foo(): kotlin.Unit
           BLOCK_BODY