#357 CMake: Calls to check_type_size require CheckTypeSize included

[Joshua T Fisher]

Hi, I noticed a small issue when attempting to use the vcpkg port of mpg123 on the wasm triplet. Something about that environment exposed that check_type_size is being used in the CMakeLists.txt without prior inclusion of CheckTypeSize. Fixing this led it to compiling and linking just fine.

Unsure if it's helpful but I've included the patch I'll be submitting to vcpkg :)

Thank you for you work on this library!

[Thomas Orgis]

You get a hard error from that? My CMake on Linux doesn't make a sound. It misses the man-pages, though. I added your fix anyway, thanks.

[Joshua T Fisher]

Yeah only when compiling for wasm with emscripten, it's very strange, I didn't see a peep on any of the other platforms.

Thanks!