Coercible solver incomplete with recursive newtypes

The following module fails to compile due to infinite recursion:

import Data.Coerce

newtype Bar a = Bar (Either a (Bar a))
newtype Age = MkAge Int

x :: Bar Age
x = coerce (Bar (Left (5 :: Int)))

It tries to coerce Bar Int to Bar Age. This is clearly doable, via tyconapp decomposition. But we don't find it. Before worrying too much about it, though, we'll wait for a real example.

Do speak up if this problem is ruining your day!

Trac metadata

Trac field	Value
Version	7.10.1-rc3
Type	Bug
TypeOfFailure	OtherFailure
Priority	low
Resolution	Unresolved
Component	Compiler
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