Infinite recursion when parsing bad AstStatDeclareClass (definition file)

[JohnnyMorganz]

Originally reported by @coderedart in JohnnyMorganz/luau-lsp#756

---

declare class Widget
    state: {string: function(string, Widget)}
end

If I copy paste the above text into a type definition file and reload the lsp, luau-lsp starts leaking memory at around 100MB+ per second until the system runs out of ram.

The culprit seems to be {string: function(string, Widget)}. The syntax is probably wrong. If I use (string, Widget) -> nil instead, there's no leak.

But just wanted to report the leak anyway, as someone else might fumble into this issue.

---

I moved this to Luau since I can repro it in Luau's codebase with

TEST_CASE_FIXTURE(Fixture, "test")
{
    LoadDefinitionFileResult result = loadDefinition(R"(
        declare class Widget
            state: {string: function(string, Widget)}
        end
    )");
}

[hgoldstein]

Thanks for the report; digging in a bit I think what's happening is that when we attempt to parse this type, we error, and the error recovery doesn't move us past the error, so we just continually parse properties until Luau gets ... OOM killed I suppose.