fix(build): distinguish vim.mpack from global require'mpack'

problem: the api of vim.mpack is not compatible with a system provided mpack
solution: don't require 'mpack' directly from the system path

src/nvim/generators/gen_api_dispatch.lua

@@ -1,4 +1,4 @@
-local mpack = require('mpack')
+local mpack = vim.mpack
 
 local hashy = require'generators.hashy'
 

src/nvim/generators/gen_api_ui_events.lua

@@ -1,4 +1,4 @@
-local mpack = require('mpack')
+local mpack = vim.mpack
 
 assert(#arg == 5)
 local input = io.open(arg[1], 'rb')

src/nvim/generators/gen_eval.lua

@@ -1,4 +1,4 @@
-local mpack = require('mpack')
+local mpack = vim.mpack
 
 local autodir = arg[1]
 local metadata_file = arg[2]

src/nvim/generators/preload.lua

@@ -4,6 +4,7 @@ package.path = srcdir .. '/src/nvim/?.lua;' ..srcdir .. '/runtime/lua/?.lua;' ..
 _G.vim = require'vim.shared'
 _G.vim.inspect = require 'vim.inspect'
 package.cpath = package.cpath .. ';' .. nlualib
+require 'nlua0'
 
 arg[0] = table.remove(arg, 1)
 return loadfile(arg[0])()