[Lua] Benchmark of localization inside for loop

--[[
output:
----------------------------
Control: 0.0091000000000008
Test A: 0.03180000000001
Test B: 0.031799999999998
----------------------------
conclusion: Difference is negligible if you localize outside loop

Note, if you remove local a,b,c from Test A here are the results:
-----------------------------------
Control: 0.0089999999999918
Test A: 0.1145
Test B: 0.033200000000011
-----------------------------------
conclusion: localize globals
--]]

local clock = os.clock

-- Control group: empty for loop for comparison to Test A and B
local sum = 0
local itr = 0
repeat
	local before = clock()
	for i=1,1000000 do
	end
	sum = sum + (clock()-before)
	itr = itr + 1
until (itr == 10)
local test_control = sum/itr -- The average time


-- TEST A
sum = 0
itr = 0
repeat
	local a,b,c
	local before = clock()
	for i=1,1000000 do
		a = 2
		b = 2
		c = a + b
	end
	sum = sum + (clock()-before)
	itr = itr + 1
until (itr == 10)
local test_a = sum/itr


-- TEST B
sum = 0
itr = 0
repeat
	local before = clock()
	for i=1,1000000 do
		local a = 2
		local b = 2
		local c = a + b
	end
	sum = sum + (clock()-before)
	itr = itr + 1
until (itr == 10)
local test_b = sum/itr

print ("Control: "..test_control)
print ("Test A: "..test_a)
print ("Test B: "..test_b)