Promote big constants for arithmetic operations.

[ptersilie]

This PR adds promotion for big constants in Lua's arithmetic operations. For this we change op_arithK by inlining op_arith_aux and adding yk_promote to the second operand.

Using the following lua program I can confirm that this indeed promotes big constants:

local sum = 0
for _ = 1,100000 do
    sum = sum + 420000
end
print(sum)

However, when running yk-benchmarks I cannot see any significant performance improvements. On the contrary bigloop and permute take a 10% performance hit. Looking into bigloop I cannot figure out where this performance hit comes from as the jit-asm of both traces is nearly identical, and YKD_STATS tells us that it is indeed trace execution that takes the hit. I've attached the output for a normal run of bigloop and a run with the new promote code, printing out jit-pre-op, jit-asm, and YKD_STATS.

NORMAL.txt
PROMOTEK.txt

[ltratt]

Is that the right PR / issue for this comment?