Fix problems with RETURNING clauses attached to UPDATEs on tables with virtual columns.

FossilOrigin-Name: 6b41b136fbfc0b56a6948f2306b69fb1d69306adb86674a15a87fe3b52062512

diff --cc manifest
index a94847ab60e35469fda816ec208b34c16812bc1b,64e8e144eb5f828088c6f574187490ccad173cbe..62f72863bec3d9d667d394129b18346d76ee2486
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\sthe\sprocessing\sof\simplied\sLIMIT\sclauses\swhen\sflattening\sa\scompound\nquery.
- D 2021-03-05T14:08:45.691
 -C Fix\sanother\sproblem\swith\sRETURNING\sclauses\sin\sUPDATEs\sagainst\stables\swith\svirtual\scolumns.
 -D 2021-03-05T15:29:22.704
++C Fix\sproblems\swith\sRETURNING\sclauses\sattached\sto\sUPDATEs\son\stables\swith\svirtual\scolumns.
++D 2021-03-05T15:42:15.578
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  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
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diff --cc manifest.uuid
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--- 2/manifest.uuid
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