KT-11750 Do not report REDECLARATION on descriptors which are not available in sources.

compiler/testData/diagnostics/tests/redeclarations/EnumName.kt

@@ -0,0 +1,3 @@
+enum class A {
+    <!REDECLARATION!>name<!>
+}

compiler/testData/diagnostics/tests/redeclarations/EnumName.txt

@@ -0,0 +1,18 @@
+package
+
+public final enum class A : kotlin.Enum<A> {
+    enum entry name
+
+    private constructor A()
+    public final override /*1*/ /*fake_override*/ val name: kotlin.String
+    public final override /*1*/ /*fake_override*/ val ordinal: kotlin.Int
+    protected final override /*1*/ /*fake_override*/ fun clone(): kotlin.Any
+    public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A): kotlin.Int
+    public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    // Static members
+    public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A
+    public final /*synthesized*/ fun values(): kotlin.Array<A>
+}