Rename test data folder according to the new test naming convention.

compiler/testData/loadKotlinCustom/enum/simpleEnum.kt

@@ -0,0 +1,5 @@
+package test
+
+enum class MyEnum {
+  ENTRY
+}

compiler/testData/loadKotlinCustom/enum/simpleEnum.txt

@@ -0,0 +1,13 @@
+namespace test
+
+internal final enum class test.MyEnum : jet.Enum<test.MyEnum> {
+    public final /*constructor*/ fun <init>(/*0*/ p0: jet.String?, /*1*/ p1: jet.Int): test.MyEnum
+    public final override /*1*/ fun name(): jet.String
+    public final override /*1*/ fun ordinal(): jet.Int
+    internal final class object test.MyEnum.<class-object-for-MyEnum> {
+        public final /*constructor*/ fun <init>(): test.MyEnum.<class-object-for-MyEnum>
+        public open val ENTRY: test.MyEnum
+        public final fun valueOf(/*0*/ value: jet.String): test.MyEnum
+        public final fun values(): jet.Array<test.MyEnum>
+    }
+}