Further improvements of the math library

[data-man]

Luau already has an improved math library compared to Lua.
Let's improve it some more.
For example, to add all functions from math.h or C++ cmath.
If you don't mind, I can take this task. :)

[zeux]

Note that all changes to the libraries or the language require an RFC, see the contributing guide (https://github.com/Roblox/luau/blob/master/CONTRIBUTING.md) and RFC readme (https://github.com/Roblox/luau/blob/master/rfcs/README.md).

Are you missing some specific functions? I think math. library atm represents a full coverage of C89 math.h; C99/C++11 added a lot of new functions; some of them are likely useful and we discussed some of them in the past, but I don't think we should be adding all of them.

[data-man]

Are you missing some specific functions?

Yes, trunc, exp2, log2, asinh, acosh and atanh at least.

[lucoile]

Most of them can be implemented with the current math functions, but a gamma function would be especially useful for all sorts of math and statistical applications. Specifically, more efficient implementations of gamma distributions, beta distributions, factorial, and binomial functions like choose.