Support LuaJIT syntax extensions

[sapphyrus]

LuaJIT extends the Lua syntax with some extra stuff:

Extensions to the Lua Parser
The parser for Lua source code treats numeric literals with the suffixes LL or ULL as signed or unsigned 64 bit integers. Case doesn't matter, but uppercase is recommended for readability. It handles both decimal (42LL) and hexadecimal (0x2aLL) literals.
The imaginary part of complex numbers can be specified by suffixing number literals with i or I, e.g. 12.5i. Caveat: you'll need to use 1i to get an imaginary part with the value one, since i itself still refers to a variable named i.

See https://luajit.org/ext_ffi_api.html#literals:~:text=Extensions%20to%20the%20Lua%20Parser

These don't get parsed correctly by luaparse, even with luaVersion set to 'LuaJIT':

var parser = require('luaparse');
var ast = parser.parse('local x = 1234ULL', {luaVersion: 'LuaJIT'});
console.log(JSON.stringify(ast));

D:\dev\node_modules\luaparse\luaparse.js:614
    throw error;
    ^
SyntaxError: [1:17] '=' expected near '<eof>'
    at raise (D:\dev\node_modules\luaparse\luaparse.js:609:26)
    at expect (D:\dev\node_modules\luaparse\luaparse.js:1298:10)
    at parseAssignmentOrCallStatement (D:\dev\node_modules\luaparse\luaparse.js:2119:5)
    at parseStatement (D:\dev\node_modules\luaparse\luaparse.js:1763:12)
    at parseBlock (D:\dev\node_modules\luaparse\luaparse.js:1700:19)
    at parseChunk (D:\dev\node_modules\luaparse\luaparse.js:1675:16)
    at end (D:\dev\node_modules\luaparse\luaparse.js:2658:17)
    at Object.parse (D:\dev\node_modules\luaparse\luaparse.js:2629:31)
    at Object.<anonymous> (D:\dev\test.js:2:18)
    at Module._compile (internal/modules/cjs/loader.js:956:30)

[fstirlitz]

Previously suggested in #57. I was privately working on a patch adapting that PR. Might merge it when I have the time.