Fix cast problem with implicit constructors.

dmd2/expression.c

@@ -11678,7 +11678,10 @@ Ltupleassign:
                         ex = ex->modifiableLvalue(sc, ex);  // allocate new slot
                         ey = new ConstructExp(loc, ex, ey);
 
+#if !IN_LLVM
+// Do not cast the value to void. Same as in 2.065.
                         e = new CastExp(e->loc, e, Type::tvoid);
+#endif
                         ey = new CastExp(ey->loc, ey, Type::tvoid);
                     }
                 }

gen/toir.cpp

@@ -1140,6 +1140,14 @@ DValue* CastExp::toElem(IRState* p)
     // get the value to cast
     DValue* u = e1->toElem(p);
 
+    // a constructor expression is casted to void in order to mark
+    // the value as unused. See expression.d, method AssignExp::semantic(),
+    // around line 11681
+    if (to == Type::tvoid && e1->op == TOKconstruct)
+    {
+        return new DNullValue(Type::tvoid, 0);
+    }
+
     // cast it to the 'to' type, if necessary
     DValue* v = u;
     if (!to->equals(e1->type))