Fixed Android warnings.

3rdparty/ocornut-imgui/imgui.cpp

@@ -8453,7 +8453,8 @@ void ImFontAtlas::RenderCustomTexData(int pass, void* p_rects)
     ImVector<stbrp_rect>& rects = *(ImVector<stbrp_rect>*)p_rects;
     if (pass == 0)
     {
-        stbrp_rect r = {};
+        stbrp_rect r;
+        memset(&r, 0, sizeof(r));
         r.w = (TEX_DATA_W*2)+1;
         r.h = TEX_DATA_H+1;
         rects.push_back(r);