Fix Issue 21441 - TypeInfo_Enum.destroy and TypeInfo_Enum.postblit not calling destroy and postblit of base type

Also offTi but as that does not seem to be implemented yet mentioning it
in the change log would be confusing.

Author: n8sh

src/object.d

@@ -459,6 +459,9 @@ class TypeInfo_Enum : TypeInfo
 
     override @property inout(TypeInfo) next() nothrow pure inout { return base.next; }
     override @property uint flags() nothrow pure const { return base.flags; }
+    override const(OffsetTypeInfo)[] offTi() const { return base.offTi; }
+    override void destroy(void* p) const { return base.destroy(p); }
+    override void postblit(void* p) const { return base.postblit(p); }
 
     override const(void)[] initializer() const
     {

test/typeinfo/Makefile

@@ -1,6 +1,6 @@
 include ../common.mak
 
-TESTS:=comparison isbaseof
+TESTS:=comparison isbaseof enum_
 
 .PHONY: all clean
 all: $(addprefix $(ROOT)/,$(addsuffix .done,$(TESTS)))

test/typeinfo/src/enum_.d

@@ -0,0 +1,21 @@
+// https://issues.dlang.org/show_bug.cgi?id=21441
+
+int dtorCount;
+int postblitCount;
+
+struct S
+{
+    this(this) { ++postblitCount; }
+    ~this() { ++dtorCount; }
+}
+
+enum E : S { _ = S.init }
+
+void main()
+{
+    E e;
+    typeid(e).destroy(&e);
+    assert(dtorCount == 1);
+    typeid(e).postblit(&e);
+    assert(postblitCount == 1);
+}