Lua & Luajit Compound Operators Patch

Adds the following operators to lua5.2.4 and luajit 2.1.0-beta3 (latest release):

Metamethods "just work", eg a+=7 will invoke __add(a, 7) and assign result to a.

Lua5.2.4 and Luajit 2.1.0 are both supported so that you can use Lua when debugging and LuaJit on release

This is distributed as a patch so that you can apply it to future versions (rather than this becoming yet another unmaintained lua/luajit fork)

Download relevent sources and then use patch and then build as usual.

Alternatively use fetch_and_apply_lua*.sh to automatically download and patch

Edit files makediff_lua*.sh to make a new lua*.patch. Set A to the unmodified source directory and B to the modified source and run the script.

Tupple assignements are not supported (no a,b,c+=1337). They do work in patched PUC lua, but not patched luajit
Increment a++; is a post-increment and should be an isolated statement (no t[a++], terminate with ;)
There is no a--;, instead use a-=1;

Luajit compound operaters based on [https://github.com/mingodad/ljsjit]

Lua compound operators SvenOlsen's powerpatch [http://lua-users.org/wiki/LuaPowerPatches] (control-f: "Compound Assignment Operators (5.2)")

To Be Done

Probably won't be done unless someone submits a PR

Support binops: &,|,^,~

Luajit binops built upon [https://github.com/LuaJIT/LuaJIT/pull/312.patch]
Lua5.2 binops from powerpatch [http://lua-users.org/wiki/LuaPowerPatches] (contorl-f: "Bitwise operators, integer division and != (5.1.4)")
Support compound binops &=, |=. Look at lua52.patch and luajit210.patch for hints as to how to hook
Support multiple assign (eg a,b,c += 1,2,3). Patched lua supports this, the bit stopping this is trying to match

Public Domain