Demo: added emscripten version. (#7915)

Author: ypujante

imgui_demo.cpp

@@ -116,6 +116,9 @@ Index of this file:
 #if !defined(_MSC_VER) || _MSC_VER >= 1800
 #include <inttypes.h>       // PRId64/PRIu64, not avail in some MinGW headers.
 #endif
+#ifdef __EMSCRIPTEN__
+#include <emscripten/version.h>     // __EMSCRIPTEN_major__ etc.
+#endif
 
 // Visual Studio warnings
 #ifdef _MSC_VER
@@ -7688,6 +7691,7 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #endif
 #ifdef __EMSCRIPTEN__
         ImGui::Text("define: __EMSCRIPTEN__");
+        ImGui::Text("Emscripten: %d.%d.%d", __EMSCRIPTEN_major__, __EMSCRIPTEN_minor__, __EMSCRIPTEN_tiny__);
 #endif
         ImGui::Separator();
         ImGui::Text("io.BackendPlatformName: %s", io.BackendPlatformName ? io.BackendPlatformName : "NULL");