Add note about using cir.copy

Author: AmrDeveloper

clang/test/CIR/CodeGen/struct.cpp

@@ -167,6 +167,7 @@ void generic_selection() {
 // CIR:   %[[B_ADDR:.*]] = cir.alloca !rec_CompleteS, !cir.ptr<!rec_CompleteS>, ["b"]
 // CIR:   %[[C_ADDR:.*]] = cir.alloca !s32i, !cir.ptr<!s32i>, ["c"]
 // CIR:   %[[D_ADDR:.*]] = cir.alloca !rec_CompleteS, !cir.ptr<!rec_CompleteS>, ["d", init]
+// TODO(cir): Call to default copy constructor should be replaced by `cir.copy` op
 // CIR:   cir.call @_ZN9CompleteSC1ERKS_(%[[D_ADDR]], %[[A_ADDR]]) nothrow : (!cir.ptr<!rec_CompleteS>, !cir.ptr<!rec_CompleteS>) -> ()
 
 // LLVM: define{{.*}} void @_Z17generic_selectionv()