Add luacheck to check builtin (#7895)

.luacheckrc

@@ -0,0 +1,74 @@
+unused_args = false
+allow_defined_top = true
+
+ignore = {
+	"131", -- Unused global variable
+	"431", -- Shadowing an upvalue
+	"432", -- Shadowing an upvalue argument
+}
+
+read_globals = {
+	"ItemStack",
+	"INIT",
+	"DIR_DELIM",
+	"dump", "dump2",
+	"fgettext", "fgettext_ne",
+	"vector",
+	"VoxelArea",
+	"profiler",
+	"Settings",
+
+	string = {fields = {"split"}},
+	table  = {fields = {"copy", "getn", "indexof", "insert_all"}},
+	math   = {fields = {"hypot"}},
+}
+
+globals = {
+	"core",
+	"gamedata",
+	os = { fields = { "tempfolder" } },
+	"_",
+}
+
+files["builtin/client/register.lua"] = {
+	globals = {
+		debug = {fields={"getinfo"}},
+	}
+}
+
+files["builtin/common/misc_helpers.lua"] = {
+	globals = {
+		"dump", "dump2", "table", "math", "string",
+		"fgettext", "fgettext_ne", "basic_dump", "game", -- ???
+		"file_exists", "get_last_folder", "cleanup_path", -- ???
+	},
+}
+
+files["builtin/common/vector.lua"] = {
+	globals = { "vector" },
+}
+
+files["builtin/game/voxelarea.lua"] = {
+	globals = { "VoxelArea" },
+}
+
+files["builtin/game/init.lua"] = {
+	globals = { "profiler" },
+}
+
+files["builtin/common/filterlist.lua"] = {
+	globals = {
+		"filterlist",
+		"compare_worlds", "sort_worlds_alphabetic", "sort_mod_list", -- ???
+	},
+}
+
+files["builtin/mainmenu"] = {
+	globals = {
+		"gamedata",
+	},
+
+	read_globals = {
+		"PLATFORM",
+	},
+}