fix Issue 15045 - hasElaborateCopyConstructor is true for struct with…

… opDispatch

Stop forwarding these special aggregate members through
opDispatch, alias this, or opDot.

 __ctor (Id.ctor)
 __dtor (Id.dtor)
 __xdtor (Id.__xdtor)
 __postblit (Id.postblit)
 __xpostblit (Id.__xpostblit)

src/mtype.d

@@ -2589,7 +2589,13 @@ public:
             ident != Id._init &&
             ident != Id._mangleof &&
             ident != Id.stringof &&
-            ident != Id.offsetof)
+            ident != Id.offsetof &&
+            // Bugzilla 15045: Don't forward special built-in member functions.
+            ident != Id.ctor &&
+            ident != Id.dtor &&
+            ident != Id.__xdtor &&
+            ident != Id.postblit &&
+            ident != Id.__xpostblit)
         {
             /* Look for overloaded opDot() to see if we should forward request
              * to it.

test/runnable/xtest46.d

@@ -7584,6 +7584,65 @@ void test14853()
     auto b1 = new Queue14853!uint;
 }
 
+/********************************************************/
+// 15045
+
+void test15045()
+{
+    void testName(T, bool r, string name)()
+    {
+        T t;
+
+        static assert(r ==          is(typeof(mixin("T."~name))));
+        static assert(r ==          is(typeof(mixin("t."~name))));
+        static assert(r == __traits(compiles, mixin("T."~name)));
+        static assert(r == __traits(compiles, mixin("t."~name)));
+        static assert(r == mixin("__traits(compiles, T."~name~")"));
+        static assert(r == mixin("__traits(compiles, t."~name~")"));
+
+        static assert(r ==                       __traits(hasMember, T, name) );
+        static assert(r ==                       __traits(hasMember, t, name) );
+        static assert(r == __traits(compiles,    __traits(getMember, T, name) ));
+        static assert(r == __traits(compiles,    __traits(getMember, t, name) ));
+        static assert(r == __traits(compiles, __traits(getOverloads, T, name) ));
+        static assert(r == __traits(compiles, __traits(getOverloads, t, name) ));
+    }
+    void test(T, bool r)()
+    {
+        testName!(T, r, "__ctor")();
+        testName!(T, r, "__dtor")();
+        testName!(T, r, "__xdtor")();
+        testName!(T, r, "__postblit")();
+        testName!(T, r, "__xpostblit")();
+    }
+
+    static struct X
+    {
+        this(int) {}
+        this(this) {}
+        ~this() {}
+    }
+
+    static struct S1
+    {
+        auto opDispatch(string name, A...)(A args) { }
+    }
+    static struct S2
+    {
+        X get() { return X(); };
+        alias get this;
+    }
+    static struct S3
+    {
+        X opDot() { return X(); };
+    }
+
+    test!(X, true)();
+    test!(S1, false)();
+    test!(S2, false)();
+    test!(S3, false)();
+}
+
 /***************************************************/
 
 int main()