In commit dbd81f7e86514498218572b9d978373b1699cc5b, a
regression was inadvertently introduced which caused derived Read
instances for record data types with fields ending in a # symbol
(using MagicHash) would no longer parse on valid output. This
is ultimately due to the same reasons as Trac #5041, as we cannot parse
a field name like foo# as a single identifier. We fix this issue
by employing the same workaround as in Trac #5041: first parse the
identifier name foo, then then symbol #.
This is accomplished by the new readFieldHash function in
GHC.Read. This will likely warrant a base-18.104.22.168 release.