RFC: Add debug.getmetatable and debug.setmetatable

[ccuser44]

Add debug.getmetatable and debug.setmetatable

Summary

Add debug.getmetatable and debug.setmetatable functions which have the same behavior as getrawmetatable and setrawmetatable.

Motivation

Vanilla Lua uses debug.getmetatable and debug.setmetatable, some executors have them also. It would be good to have more compatibility with vanilla Lua as it's odd that there are functions that to the exact same thing as their vanilla Lua counterparts but have a different name.

Design

• debug.getmetatable functions the same as getrawmetatable. ie. it always returns the real metatable of the object even if it is spoofed via __metatable metamethod.
• debug.setmetatable functions the same as setrawmetatable. ie. it always sets the real metatable of the object even if it is spoofed via __metatable metamethod.

Drawbacks

Not much, have to add both the functions to the debug. library.

Alternatives

The alternative is just to use getrawmetatable and setrawmetatable. The impact of using them is small but it's still a good thing to have functions be on par with vanilla Lua.