message: Fixed GCC zealous warnings
diff: #pragma GCC diagnostic ignored "-Wconversion" // warning: conversion to 'xxxx' from 'xxxx' may alter its value
  #pragma GCC diagnostic ignored "-Wcast-qual" // warning: cast from type 'xxxx' to type 'xxxx' casts away qualifiers
  #pragma GCC diagnostic ignored "-Wformat-nonliteral" // warning: format not a string literal, format string not checked
  +#pragma GCC diagnostic ignored "-Wstrict-overflow" // warning: assuming signed overflow does not occur when assuming that (X - c) > X is always false
  #endif
  // Enforce cdecl calling convention for functions called by the standard library, in case compilation settings changed the default to e.g. __vectorcall
  @@ -4876,6 +4877,7 @@ static ImGuiWindow* GetFrontMostModalRootWindow()
  static void ClosePopupToLevel(int remaining)
  {
  + IM_ASSERT(remaining >= 0);
  ImGuiContext& g = *GImGui;
  ImGuiWindow* focus_window = (remaining > 0) ? g.OpenPopupStack[remaining-1].Window : g.OpenPopupStack[0].ParentWindow;
  if (g.NavLayer == 0)
  @@ -11215,7 +11217,7 @@ bool ImGui::BeginMenu(const char* label, bool enabled)
  if (!enabled) // explicitly close if an open menu becomes disabled, facilitate users code a lot in pattern such as 'if (BeginMenu("options", has_object)) { ..use object.. }'
  want_close = true;
  if (want_close && IsPopupOpen(id))
  - ClosePopupToLevel(GImGui->CurrentPopupStack.Size);
  + ClosePopupToLevel(g.CurrentPopupStack.Size);
  if (!menu_is_open && want_open && g.OpenPopupStack.Size > g.CurrentPopupStack.Size)
  {
  