Misc: Fix custom assertion macro failing to compile imgui.cpp (#5378)

imgui.cpp

@@ -15658,7 +15658,7 @@ static void ImGui::DockNodePreviewDockSetup(ImGuiWindow* host_window, ImGuiDockN
     ImGuiDockNode* root_payload_as_host = root_payload->DockNodeAsHost;
     ImGuiDockNode* ref_node_for_rect = (host_node && !host_node->IsVisible) ? DockNodeGetRootNode(host_node) : host_node;
     if (ref_node_for_rect)
-        IM_ASSERT(ref_node_for_rect->IsVisible);
+        IM_ASSERT(ref_node_for_rect->IsVisible == true);
 
     // Filter, figure out where we are allowed to dock
     ImGuiDockNodeFlags src_node_flags = root_payload_as_host ? root_payload_as_host->MergedFlags : root_payload->WindowClass.DockNodeFlagsOverrideSet;