Fonts: Change ImFontConfig::FontNo back to int from S8 (#8775)

When used with FreeType this value is passed as `face_index` which needs to be 32-bits.

# Conflicts:
#	docs/CHANGELOG.txt

docs/CHANGELOG.txt

@@ -50,6 +50,10 @@ Other changes:
 - Fonts: set a maximum font size of 512.0f at ImGui:: API level to reduce
   edge cases (e.g. out of memory errors). ImDrawList:: API doesn't have the
   constraint. (#8758)
+- Fonts: Restore ImFontConfig::FontNo being a 32-bits value as this is needed
+  to pass full range of information into e.g. FreeType's face_index, as higher
+  bits are used from FreeType 2.6.1. (#8775) [@Valakor]
+  (the field has been erroneously reduced from 32-bits to 8-bit in 1.92.0)
 - Textures: Fixed support for `#define ImTextureID_Invalid` to non-zero value:
   ImTextureData() was incorrectly cleared with zeroes. (#8745) [@rachit7645]
 - Demo: Added "Text -> Font Size" demo section. (#8738) [@Demonese]

imgui.h

@@ -3473,9 +3473,9 @@ struct ImFontConfig
     bool            MergeMode;              // false    // Merge into previous ImFont, so you can combine multiple inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs). You may want to use GlyphOffset.y when merge font of different heights.
     bool            PixelSnapH;             // false    // Align every glyph AdvanceX to pixel boundaries. Useful e.g. if you are merging a non-pixel aligned font with the default font. If enabled, you can set OversampleH/V to 1.
     bool            PixelSnapV;             // true     // Align Scaled GlyphOffset.y to pixel boundaries.
-    ImS8            FontNo;                 // 0        // Index of font within TTF/OTF file
     ImS8            OversampleH;            // 0 (2)    // Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1 or 2 depending on size. Note the difference between 2 and 3 is minimal. You can reduce this to 1 for large glyphs save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
     ImS8            OversampleV;            // 0 (1)    // Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1. This is not really useful as we don't use sub-pixel positions on the Y axis.
+    ImWchar         EllipsisChar;           // 0        // Explicitly specify Unicode codepoint of ellipsis character. When fonts are being merged first specified ellipsis will be used.
     float           SizePixels;             //          // Size in pixels for rasterizer (more or less maps to the resulting font height).
     const ImWchar*  GlyphRanges;            // NULL     // *LEGACY* THE ARRAY DATA NEEDS TO PERSIST AS LONG AS THE FONT IS ALIVE. Pointer to a user-provided list of Unicode range (2 value per range, values are inclusive, zero-terminated list).
     const ImWchar*  GlyphExcludeRanges;     // NULL     // Pointer to a small user-provided list of Unicode ranges (2 value per range, values are inclusive, zero-terminated list). This is very close to GlyphRanges[] but designed to exclude ranges from a font source, when merging fonts with overlapping glyphs. Use "Input Glyphs Overlap Detection Tool" to find about your overlapping ranges.
@@ -3484,11 +3484,11 @@ struct ImFontConfig
     float           GlyphMinAdvanceX;       // 0        // Minimum AdvanceX for glyphs, set Min to align font icons, set both Min/Max to enforce mono-space font. Absolute value for default size, other sizes will scale this value.
     float           GlyphMaxAdvanceX;       // FLT_MAX  // Maximum AdvanceX for glyphs
     float           GlyphExtraAdvanceX;     // 0        // Extra spacing (in pixels) between glyphs. Please contact us if you are using this. // FIXME-NEWATLAS: Intentionally unscaled
+    ImU32           FontNo;                 // 0        // Index of font within TTF/OTF file
     unsigned int    FontLoaderFlags;        // 0        // Settings for custom font builder. THIS IS BUILDER IMPLEMENTATION DEPENDENT. Leave as zero if unsure.
     //unsigned int  FontBuilderFlags;       // --       // [Renamed in 1.92] Ue FontLoaderFlags.
     float           RasterizerMultiply;     // 1.0f     // Linearly brighten (>1.0f) or darken (<1.0f) font output. Brightening small fonts may be a good workaround to make them more readable. This is a silly thing we may remove in the future.
     float           RasterizerDensity;      // 1.0f     // [LEGACY: this only makes sense when ImGuiBackendFlags_RendererHasTextures is not supported] DPI scale multiplier for rasterization. Not altering other font metrics: makes it easy to swap between e.g. a 100% and a 400% fonts for a zooming display, or handle Retina screen. IMPORTANT: If you change this it is expected that you increase/decrease font scale roughly to the inverse of this, otherwise quality may look lowered.
-    ImWchar         EllipsisChar;           // 0        // Explicitly specify Unicode codepoint of ellipsis character. When fonts are being merged first specified ellipsis will be used.
 
     // [Internal]
     ImFontFlags     Flags;                  // Font flags (don't use just yet, will be exposed in upcoming 1.92.X updates)

misc/freetype/imgui_freetype.cpp

@@ -174,7 +174,7 @@ struct ImGui_ImplFreeType_FontSrcBakedData
 
 bool ImGui_ImplFreeType_FontSrcData::InitFont(FT_Library ft_library, ImFontConfig* src, ImGuiFreeTypeLoaderFlags extra_font_loader_flags)
 {
-    FT_Error error = FT_New_Memory_Face(ft_library, (uint8_t*)src->FontData, (uint32_t)src->FontDataSize, (uint32_t)src->FontNo, &FtFace);
+    FT_Error error = FT_New_Memory_Face(ft_library, (uint8_t*)src->FontData, (FT_Long)src->FontDataSize, (FT_Long)src->FontNo, &FtFace);
     if (error != 0)
         return false;
     error = FT_Select_Charmap(FtFace, FT_ENCODING_UNICODE);