Track the local binding that a prefixed type reference is linked to

[JohnnyMorganz]

Right now, all local bindings are nicely linked together as they share a pointer to the same AstLocal. But the same is not true for type references

Consider the following code:

local Types = require("path/to/types")

type Foo = Types.Foo

It would be nice to be able to link the Types in Types.Foo to the local definition.
Use case: if a user requests to rename the "Types" local variable, it should rename the imported type prefix (and vice versa).

From first glance, I think this is doable by storing the prefix as an AstLocal here, and tracking it appropriately:

luau/Ast/include/Luau/Ast.h

Lines 883 to 899 in 74c5320

	class AstTypeReference : public AstType
	{
	public:
	LUAU_RTTI(AstTypeReference)
	AstTypeReference(const Location& location, std::optional<AstName> prefix, AstName name, std::optional<Location> prefixLocation,
	const Location& nameLocation, bool hasParameterList = false, const AstArray<AstTypeOrPack>& parameters = {});
	void visit(AstVisitor* visitor) override;
	bool hasParameterList;
	std::optional<AstName> prefix;
	std::optional<Location> prefixLocation;
	AstName name;
	Location nameLocation;
	AstArray<AstTypeOrPack> parameters;
	};

Or maybe you have other ideas