That's not it, I mean the "declare" statements that aren't even listed in the grammar, but are needed to give the type checker information about C API exports; I had to discover them by digging through source code. The analyzer even hardcodes a bunch of them.
luau-lsp for example ships this globalTypes.d.lua file[1] for Roblox development and lets you configure your own.
https://luau-lang.org/typecheck
https://luau-lang.org/grammar