[Feature request] Support for the upvalue limit

Functions in Lua 5.1 (and LuaJIT) can only reference up to 60 upvalues.

For example, the following code does not compile in Lua 5.1 ("lua5.1: upvals.lua:4: function at line 3 has more than 60 upvalues") but LuaLS accepts it without any warning when the version is set to 5.1. Ideally this would be handled directly in the parser similar to the 200 local limits.

local a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61

function Foo()
	print(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61)
end

Start in the parser where the existing 200-local limit is handled and trace how upvalues are counted for Lua 5.1 and LuaJIT. Add the corresponding limit warning for functions exceeding 60 upvalues, then run the parser tests or add a case based on the example to verify that Lua 5.1 reports the error.