Added Luau global import optimisation

[ccuser44]

Make compiler localize Luau globals if env is safe
For this to happen the parser has to know what globals are used and if env is safe so a pre-made lex tree must be used.

NOTE: Unfortunately uses a quick hack to add lex tokens in the lexer instead of having a parser function only add a local set expression containing the globals to the main chunk.

[Dimenpsyonal]

I'm gonna be real, all these changes to code execution are probably going to backfire horribly

[PurpleCreativity]

You Live only Once @Dimenpsyonal

[ccuser44]

PoF:

Performance:
Loadstring no-localisation: 3.884305715560913 - 3.8650588989257812 - 3.9003798961639404
Loadstring localisation: 3.6001365184783936 - 3.589552879333496 - 3.555936813354492
Raw Luau: 0.07147550582885742 - 0.07510924339294434 - 0.06685996055603027

Perf script:

local primes = 
	{
		0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
		0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
		0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
		0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
		0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
		0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
		0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
		0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
		0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
		0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
		0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
		0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
		0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
		0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
		0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
		0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
	}

local function toHex(str)
	local result = str:gsub('.', function (char)
		return string.format("%02x", char:byte())
	end)

	return result
end

local function toBytes(value, length)
	local str = ""

	for i = 1, length do
		local rem = value % 256
		str = string.char(rem) .. str
		value = (value - rem) / 256
	end

	return str
end

local function readInt32(buffer, index)
	local value = 0

	for i = index, index + 3 do 
		value = (value * 256) + string.byte(buffer, i)
	end

	return value
end

local function digestBlock(msg, i, hash)
	local digest = {}

	for j = 1, 16 do 
		digest[j] = readInt32(msg, i + (j - 1) * 4) 
	end

	for j = 17, 64 do
		local v = digest[j - 15]
		local s0 = bit32.bxor(bit32.rrotate(v, 7), bit32.rrotate(v, 18), bit32.rshift(v, 3))

		v = digest[j - 2]
		digest[j] = digest[j - 16] + s0 + digest[j - 7] + bit32.bxor(bit32.rrotate(v, 17), bit32.rrotate(v, 19), bit32.rshift(v, 10))
	end

	local a, b, c, d, e, f, g, h = unpack(hash)

	for i = 1, 64 do
		local s0 = bit32.bxor(bit32.rrotate(a, 2), bit32.rrotate(a, 13), bit32.rrotate(a, 22))
		local maj = bit32.bxor(bit32.band(a, b), bit32.band(a, c), bit32.band(b, c))

		local t2 = s0 + maj
		local s1 = bit32.bxor(bit32.rrotate(e, 6), bit32.rrotate(e, 11), bit32.rrotate(e, 25))

		local ch = bit32.bxor(bit32.band(e, f), bit32.band(bit32.bnot(e), g))
		local t1 = h + s1 + ch + primes[i] + digest[i]

		h, g, f, e, d, c, b, a = g, f, e, d + t1, c, b, a, t1 + t2
	end

	hash[1] = bit32.band(hash[1] + a)
	hash[2] = bit32.band(hash[2] + b)
	hash[3] = bit32.band(hash[3] + c)
	hash[4] = bit32.band(hash[4] + d)
	hash[5] = bit32.band(hash[5] + e)
	hash[6] = bit32.band(hash[6] + f)
	hash[7] = bit32.band(hash[7] + g)
	hash[8] = bit32.band(hash[8] + h)
end

local function sha256(msg)
	do
		local extra = 64 - ((#msg + 9) % 64)
		local len = toBytes(8 * #msg, 8)

		msg = msg .. '\128' .. string.rep('\0', extra) .. len
		assert(#msg % 64 == 0)
	end

	local hash = 
		{
			0x6a09e667,
			0xbb67ae85,
			0x3c6ef372,
			0xa54ff53a,
			0x510e527f,
			0x9b05688c,
			0x1f83d9ab,
			0x5be0cd19,	
		}

	for i = 1, #msg, 64 do 
		digestBlock(msg, i, hash)
	end

	local result = ""

	for i = 1, 8 do
		local value = hash[i]
		result = result .. toBytes(value, 4)
	end

	return toHex(result)
end

------------------------------------------------------------------

local input = string.rep(".", 26e4)

local now = tick()
local result = sha256(input)

print(tick() - now)
print(result)

------------------------------------------------------------------

[ccuser44]

Unfortunately I just dont have the time to add the parser logic for the env replace so I had to use a hack for now because im very busy

[ccuser44]

Before all optimizations (#1017 (affects), #1470 (affects), #1472, #1478 (affects), #1486 (affects)): 4.669577121734619 - 4.667480707168579 - 4.654944181442261

The getfenv removal + update + JIT + concat optimization + global localization shaved off about 1.5s. Ie. down from 4.7s to 3.5s

The last thing to add is full global localisation via parser logic + lexer set tagging:

• Localize all library imports too to their own local variables
• Compile const table.create to NEWTABLE with size set