Lua-emcc for execution in-browser updated with 5.5.0-beta (and some older versions)

[Родион Горковенко]

Hi Friends!

Some time ago I made a hasty "javascript" build of Lua - it is mostly useless, but still can help:
- it could be executed in a browser sandbox (the link below)
- even allows to share some runnable code as for a demo (click "advanced")
- could be added to some web-page to provide basic browser-scripting functionality in Lua (fetch lua.js and lua.wasm from project source and follow instructions).

It just came to my mind to update it to 5.5.0-beta and also I added here a few earlier versions (5.4.8, 5.3.6, 5.2.4, 5.1.5 and 5.0.3) - not that I think they are very useful now (except for some curiosity and backward compatibility experiments) - but it appeared just a matter of a few minutes, so why not :)

https://rodiongork.github.io/lua-emcc/

Feel free to check it or even use it - I'm curious if the various versions work properly. 

Also a review request - please see a "build.sh" script with its defines used for building the code - perhaps you may hint if some new important define is missing or some old is irrelevant. Please find it on the project source page https://github.com/rodiongork/lua-emcc

sincerely yours,

Rodion