offlineasm: fix macro scoping

[Tadeu Zagallo]

In the code below, the reference to `f` in `g`, which should refer to the outer macro definition will instead refer to the f argument of the anonymous macro passed to `g`. That leads to this code failing to compile (f expected 0 args but got 1).

```
macro f(x)
    move x, t0
end

macro g(fn)
    fn(macro () f(42) end)
end

g(macro(f) f() end)
```

[Tadeu Zagallo]

Created attachment 350594 [details]
Patch

[Tadeu Zagallo]

Created attachment 350670 [details]
fix error reporting

[Mark Lam]

Comment on attachment 350670 [details]
fix error reporting

View in context: https://bugs.webkit.org/attachment.cgi?id=350670&action=review

r+ if your local testing doesn't show any issues and EWS bots are happy.

> Source/JavaScriptCore/offlineasm/transform.rb:137
> +$uniqueVarID = 0

nit: Let's name this uniqueMacroVarID since it's only used for macro vars.

[Tadeu Zagallo]

Created attachment 350696 [details]
patch for landing

[WebKit Commit Bot]

Comment on attachment 350696 [details]
patch for landing

Clearing flags on attachment: 350696

Committed r236434: <https://trac.webkit.org/changeset/236434>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/44744036>