Make use of covering indexes in the OR optimization.

FossilOrigin-Name: 9de3d7123007636aa97da1c70bc34344b0391078

diff --cc manifest
index abb80cb617bbcb693dc9bb76d601583b94cfeb5b,6b3a40d3f90a9cb4b32b7ed172ef41990bd92e3e..9e56090535a7917fbef863e9ee1a5408a6e1dde7
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Avoid\sunnecessary\sWHERE\sclause\sterm\stests\swhen\scoding\sa\sjoin\swhere\sone\sof\sthe\stables\scontains\sa\sOR\sconstraint.
- D 2016-01-29T18:11:04.923
 -C Change\sthe\sP4_INTARRAY\sso\sthat\salways\sbegins\swith\sa\slength\sinteger.\s\sPrint\nthe\scontent\sof\sthe\sINTARRAY\son\sEXPLAIN\soutput.
 -D 2016-01-30T00:45:18.967
++C Make\suse\sof\scovering\sindexes\sin\sthe\sOR\soptimization.
++D 2016-01-30T02:10:38.644
  F Makefile.in 027c1603f255390c43a426671055a31c0a65fdb4
  F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
  F Makefile.msc 72b7858f02017611c3ac1ddc965251017fed0845
@@@ -1422,8 -1422,7 +1422,8 @@@ F tool/vdbe_profile.tcl 246d0da094856d7
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P 2910ef64097b890c9f8929bf609ea2827db7ac97 ab94603974a0ad5342e5aee27603162652e70492
- R a5e195d58a480f7623421e36c529b8b4
- T +closed ab94603974a0ad5342e5aee27603162652e70492
 -P 7cb697f82932a2581af69350117a29c9c8a2544f
++P 512caa1ad30e6f699e2d006d5ab7674d55d2c746 6c520d5726e80b4251338c43c405270d150ea81e
+ R e4149e0b983ab1835709b124e27b8f90
++T +closed 6c520d5726e80b4251338c43c405270d150ea81e
  U drh
- Z e540fd89ce55e7aa63a8bd5d9b52b2c8
 -Z 9c9e55627bd1b33e50ca6caf5cedf1b5
++Z 625eb895cdbe3aba3d382c8d078d5321

diff --cc manifest.uuid
index ebf0893a7586d6e5bc7bff7c918710fc278301b6,95c87154e9462b46b8de7777592671132250c668..a752c98ceaef7a036082cebd509c50d396e7c290
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 512caa1ad30e6f699e2d006d5ab7674d55d2c746
 -6c520d5726e80b4251338c43c405270d150ea81e
++9de3d7123007636aa97da1c70bc34344b0391078