Merge experimental changes improving optimization of DISTINCT queries with the trunk.

FossilOrigin-Name: 45e581bff7a75db6c9a2c45b73d034d0b8a166d1

diff --cc manifest
index 52a2aaa76b2b54e5724c28a9be8dd6a950d78f6d,5d0c1374862dd16ff72afa5a42af95fc8efcb6cd..ea458a6adad7e6ff29a7293b3fb567a4fc271fd7
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Test\scase\sfor\sticket\s[d6ddba6706353915ceed]
- D 2011-07-01T14:22:04.191
 -C Fix\sa\sbroken\sassert()\sin\swhere.c.
 -D 2011-07-02T06:44:05.968
++C Merge\sexperimental\schanges\simproving\soptimization\sof\sDISTINCT\squeries\swith\sthe\strunk.
++D 2011-07-02T09:46:52.496
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in c1d7a7f4fd8da6b1815032efca950e3d5125407e
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -949,7 -950,7 +950,7 @@@ F tool/symbols.sh bc2a3709940d47c8ac8e0
  F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
  F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
  F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
- P 009c96ea7836edf75d65b150055e920079bb45e3
- R c79f1fc1420004e852fc4dd4b2df1b0e
- U drh
- Z fee6ccae1aad0120ae0a15394efb76ef
 -P e56be74eabc03d1a524d96aa4e87102dea4e348e
++P 953e169e8a7dac05a0b56b4ef5d500ec8399d37f 090b29177fbc9faa83b560d92ddc3710d291776e
+ R a0416d3328a66ac3932394627191f7dc
+ U dan
 -Z 6cc3cca355617f23d46e4dc8112cd183
++Z a35e180a4755a506b249eeb5b9af1ec2

diff --cc manifest.uuid
index f76287d58604bf20134236e6428a1496d76c0a2f,c0528273a083674d6dce6d62c97cd5b10b5cc1b1..e8854363145081a819b5840cc45102c2fc57dfdd
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 953e169e8a7dac05a0b56b4ef5d500ec8399d37f
 -090b29177fbc9faa83b560d92ddc3710d291776e
++45e581bff7a75db6c9a2c45b73d034d0b8a166d1