storage: fix local_call not finding persistent func

Currently, if function was created as C stored procedure or as Lua
persistent function (with body argument) via box.schema.func.create,
all types of router.call and router.map_callrw cannot find it and
return `Procedure 'name' is not defined` error.

This is cased by the fact that both of these function use local_call,
which invokes net_box.self.call. It didn't work with these type of
functions before Tarantool 3.0.0-beta1-18. Let's use box.func, where
it's needed instead of net_box.self.call in local_call.

Closes #436

NO_DOC=bugfix

test/storage-luatest/storage_1_test.lua

@@ -168,3 +168,17 @@ test_group.test_recovery_bucket_stat = function(g)
 
     vtest.cluster_cfg(g, global_cfg)
 end
+
+test_group.test_local_call = function(g)
+    -- box.func was introduced in 2.2.1.
+    t.run_only_if(vutil.version_is_at_least(2, 2, 1, nil, 0, 0))
+    g.replica_1_a:exec(function()
+        local body = [[function(a, b) return a + b end]]
+        box.schema.func.create('sum', {body = body})
+        local bid = _G.get_first_bucket()
+        local ok, ret = ivshard.storage.call(bid, 'read', 'sum', {1, 2})
+        ilt.assert_equals(ret, 3)
+        ilt.assert_equals(ok, true)
+        box.func.sum:drop()
+    end)
+end

vshard/storage/init.lua

@@ -265,10 +265,29 @@ end
 -- The function returns pcall() as is, because is used from places where
 -- exceptions are not allowed.
 --
-local function local_call(func_name, args)
+local local_call
+
+if util.version_is_at_least(3, 0, 0, 'beta', 1, 18) then
+
+local_call = function(func_name, args)
     return pcall(netbox_self_call, netbox_self, func_name, args)
 end
 
+else -- < 3.0.0-beta1-18
+
+-- net_box.self.call() doesn't work with C stored and Lua persistent
+-- functions before 3.0.0-beta1-18, so we try to call it via func.call
+-- API prior to using net_box.self API.
+local_call = function(func_name, args)
+    local func = box.func and box.func[func_name]
+    if not func then
+        return pcall(netbox_self_call, netbox_self, func_name, args)
+    end
+    return pcall(func.call, func, args)
+end
+
+end
+
 local function master_call(replicaset, func, args, opts)
     local deadline = fiber_clock() + opts.timeout
     local did_first_attempt = false