When using an index on an expression, try to use the columns of the index

rather than pulling columns from the table and reevaluating the expression.

FossilOrigin-Name: a47efb7c8520a01110ce3b3531ebe1bab6720780d67fba001992c44c5807d332

diff --cc manifest
index ce780fd1791de884c30281b3f9f675972877e784,09a2684db46174246e5241b9e90da2a54e7558d3..944af9d4e51f825a2a7ce1e93b5390e698e4ec86
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Smaller\sand\sfaster\svdbeFreeOpArray()
- D 2017-04-10T20:51:21.112
 -C Improved\scomments.\s\sFix\sa\sproblem\swhen\san\sindexed\sexpression\sis\sused\sin\san\nORDER\sBY\sclause.
 -D 2017-04-11T01:01:27.332
++C When\susing\san\sindex\son\san\sexpression,\stry\sto\suse\sthe\scolumns\sof\sthe\sindex\nrather\sthan\spulling\scolumns\sfrom\sthe\stable\sand\sreevaluating\sthe\sexpression.
++D 2017-04-11T01:30:42.675
  F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
  F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
  F Makefile.msc a4c0613a18663bda56d8cf76079ab6590a7c3602e54befb4bbdef76bcaa38b6a
@@@ -1570,7 -1570,7 +1570,8 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P efd1702ae8da8e0dd3d2ee7bd5a1bd8aeff2b370498e404041fcb406fdaf72e4
- R 08e07e2df33f53e5c795c66423297623
 -P 8978465f335925378d3aa99df6190ce6a1ee6b130205ccc493f2399803844760
++P e052436d9f54b785facd661adc648512356b831c0547aa8f347ebf4bd8ef1254 c59eaf2b7cd2596733f349fc0fe979f71fd29bd73152a0c57066e0b69d5b7a4a
+ R 1b0a9c05391f59848f876fd33c1876bb
++T +closed c59eaf2b7cd2596733f349fc0fe979f71fd29bd73152a0c57066e0b69d5b7a4a
  U drh
- Z fe1f0eec29c92bb8a2e730e35a741ada
 -Z 21e604ae631dfab7b9082f6214d51689
++Z d8fc420323e8e66f4fe145abb4c72eca

diff --cc manifest.uuid
index bbd127fb5717397e77633f561748bc132cfc96c3,f5bcb5c58b479a9c894b057779ed191d8ca18db4..5aefa945285be30b8ef71323a8263b8e24e02d07
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- e052436d9f54b785facd661adc648512356b831c0547aa8f347ebf4bd8ef1254
 -c59eaf2b7cd2596733f349fc0fe979f71fd29bd73152a0c57066e0b69d5b7a4a
++a47efb7c8520a01110ce3b3531ebe1bab6720780d67fba001992c44c5807d332