Fix Issue 21680 - inconsistent error on typeof({ return field; }())

[BorisCarvajal]

No description provided.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	21680	normal	inconsistent error on typeof\(\{ return field; \}\(\)\)

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#12251"

[Geod24]

Such a simple bugfix could have gone to stable BTW.

[WalterBright]

It might be simple in terms of lines of code, but forward reference tweaking has historically been a minefield.