Fonts: make ImFont::Sources a vector.

Later it should become a ImSpan<>

imgui.h

@@ -3759,8 +3759,7 @@ struct ImFont
     // Conceptually Sources[] is the list of font sources merged to create this font.
     ImGuiID                     FontId;             // Unique identifier for the font
     float                       DefaultSize;        // 4     // in  // Default font size
-    short                       SourcesCount;       // 2     // in  // Number of ImFontConfig involved in creating this font. Usually 1, or >1 when merging multiple font sources into one ImFont.
-    ImFontConfig*               Sources;            // 4-8   // in  // Pointer within ContainerAtlas->Sources[], to SourcesCount instances
+    ImVector<ImFontConfig*>     Sources;            // 16    // in  // List of sources. Pointers within ContainerAtlas->Sources[]
     ImWchar                     EllipsisChar;       // 2-4   // out // Character used for ellipsis rendering ('...').
     ImWchar                     FallbackChar;       // 2-4   // out // Character used if a glyph isn't found (U+FFFD, '?')
     float                       Scale;              // 4     // in  // Base font scale (~1.0f), multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
@@ -3773,7 +3772,7 @@ struct ImFont
     IMGUI_API ImFontBaked*      GetFontBaked(float font_size);  // Get or create baked data for given size
     IMGUI_API bool              IsGlyphInFont(ImWchar c);
     bool                        IsLoaded() const                { return ContainerAtlas != NULL; }
-    const char*                 GetDebugName() const            { return Sources ? Sources[0].Name : "<unknown>"; } // Fill ImFontConfig::Name.
+    const char*                 GetDebugName() const            { return Sources.Size ? Sources[0]->Name : "<unknown>"; } // Fill ImFontConfig::Name.
 
     // [Internal] Don't use!
     // 'max_width' stops rendering after a certain width (could be turned into a 2d size). FLT_MAX to disable.