The IS operator can now use indexes the same as the == operator.

FossilOrigin-Name: 3428043cd00294457548bb07ada2ad526b6532d6

diff --cc manifest
index 0c5a5294e3b04b9bc7259cf3c60a13ee83cb8756,be7f8e70259d826a298faba4d1f6cab19a5218d6..06d5eb49cfcb848c66efdfe72230afcc2f723565
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Enhancements\sto\sthe\sMSVC\smakefile.
- D 2015-05-13T04:50:30.732
 -C A\sfew\smore\stest\scases\sfor\sthe\sIS\soperator.
 -D 2015-05-14T14:03:21.962
++C The\sIS\soperator\scan\snow\suse\sindexes\sthe\ssame\sas\sthe\s==\soperator.
++D 2015-05-14T14:32:11.685
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in edfc69769e613a6359c42c06ea1d42c3bece1736
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -1258,7 -1258,7 +1258,8 @@@ F tool/vdbe_profile.tcl 67746953071a9f8
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P b33f1bacfdb34fe66b7b073e68bfac38498d6e88
- R 786cf9bafb843a30daaea508385a36b1
- U mistachkin
- Z cf0d8cd171ac487c0fd87c289759c254
 -P b3676377b257bd8bb7fefe9c365d76cdc9e44856
++P 59e3e9e764440b7feaafadff74f422535d21bca2 f397c8622ae5a36a71f81d9f2549ca314005ece5
+ R bdc88e4814b826734527d4ac723cdd70
++T +closed f397c8622ae5a36a71f81d9f2549ca314005ece5
+ U drh
 -Z e30ac775b8d8ec0dc6dc3a554502ca78
++Z 2145c2897b1f3b7880cf6c9a6c38a0d4

diff --cc manifest.uuid
index af09740391caad5f8097efb6a468eab85473077d,db9f3726324f1eba0165090af5c767fa98869278..6cf0e2c25d8203f72a2dd57d9f12d4c88436f337
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 59e3e9e764440b7feaafadff74f422535d21bca2
 -f397c8622ae5a36a71f81d9f2549ca314005ece5
++3428043cd00294457548bb07ada2ad526b6532d6