message: fix sh generation when -d is used
  When -d was used, the radiance and irradiance ended-up being
  swapped in the final file.
  Also rename g_coefficients to g_sh_coefficients.
diff: @@ -82,7 +82,7 @@ static float g_sh_window = 0.0f;
  static bool g_noclamp = false;
  static ShFile g_sh_file = ShFile::SH_NONE;
  static utils::Path g_sh_filename;
  -static std::unique_ptr<filament::math::float3[]> g_coefficients;
  +static std::unique_ptr<filament::math::float3[]> g_sh_coefficients;
  static bool g_is_mipmap = false;
  static utils::Path g_is_mipmap_dir;
  @@ -696,7 +696,7 @@ void sphericalHarmonics(utils::JobSystem& js, const utils::Path& iname, const Cu
  sh = CubemapSH::computeSH(js, inputCubemap, g_sh_compute, g_sh_irradiance);
  }
  - if (g_sh_window) {
  + if (g_sh_window > 0) {
  CubemapSH::windowSH(sh, g_sh_compute, g_sh_window);
  }
  @@ -749,7 +749,8 @@ void sphericalHarmonics(utils::JobSystem& js, const utils::Path& iname, const Cu
  }
  { // save a file with the "other one" (irradiance or radiance)
  - sh = CubemapSH::computeSH(js, inputCubemap, g_sh_compute, !g_sh_irradiance);
  + std::unique_ptr<filament::math::float3[]> sh
  + = CubemapSH::computeSH(js, inputCubemap, g_sh_compute, !g_sh_irradiance);
  CubemapSH::renderSH(js, cm, sh, g_sh_compute);
  std::string basename = iname.getNameWithoutExtension();
  utils::Path filePath =
  @@ -759,7 +760,7 @@ void sphericalHarmonics(utils::JobSystem& js, const utils::Path& iname, const Cu
  }
  }
  // Stash the computed coefficients in case we need to use them at a later stage (e.g. KTX gen)
  - g_coefficients = std::move(sh);
  + g_sh_coefficients = std::move(sh);
  }
  void outputSh(std::ostream& out,
  @@ -956,11 +957,11 @@ void iblRoughnessPrefilter(utils::JobSystem& js, const utils::Path& iname,
  }
  if (g_type == OutputType::KTX) {
  - if (g_coefficients) {
  + if (g_sh_coefficients) {
  std::ostringstream sstr;
  for (ssize_t l = 0; l < g_sh_compute; l++) {
  for (ssize_t m = -l; m <= l; m++) {
  - auto v = g_coefficients[CubemapSH::getShIndex(m, (size_t) l)];
  + auto v = g_sh_coefficients[CubemapSH::getShIndex(m, (size_t) l)];
  sstr << v.r << " " << v.g << " " << v.b << "\n";
  }
  }
  