util.array: Fix new() library function

Backport of ffe4adbd2af9 since new was added in the 0.12 branch

spec/util_array_spec.lua

@@ -1,6 +1,13 @@
 local array = require "util.array";
 describe("util.array", function ()
 	describe("creation", function ()
+		describe("new", function ()
+			it("works", function ()
+				local a = array.new({"a", "b", "c"});
+				assert.same({"a", "b", "c"}, a);
+			end);
+		end);
+
 		describe("from table", function ()
 			it("works", function ()
 				local a = array({"a", "b", "c"});

util/array.lua

@@ -35,7 +35,9 @@ local function new_array(self, t, _s, _var)
 	return setmetatable(t or {}, array_mt);
 end
 
-array.new = new_array;
+function array.new(t)
+	return setmetatable(t or {}, array_mt);
+end
 
 function array_mt.__add(a1, a2)
 	local res = new_array();