Simplification and performance improvement to the logic that factors

constant expressions ouf of inner loops.

FossilOrigin-Name: ee9353fdf3c8f19cd3c344ea8fb7c6d13cadd632

diff --cc manifest
index 7a24f800bc6e1fb8bf4cbeac45c24ee4c14b295f,9ae591ea2a260a1b8d3e15cd3b71e8c696652df0..a99086baf0dbbfbfa496da817d455124460deea8
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\stestcase\smisc7-16\sso\sthat\sit\sworks\swith\sthe\snew\sUNIQUE\sconstraint\serror\nmessage\sformat.
- D 2013-11-16T12:56:46.327
 -C Add\sALWAYS\sand\sNEVER\smacros\sto\scurrently\sunreachable\sbut\simportant\sbranches\sin\nsqlite3ExprCompare().
 -D 2013-11-15T20:06:26.444
++C Simplification\sand\sperformance\simprovement\sto\sthe\slogic\sthat\sfactors\s\nconstant\sexpressions\souf\sof\sinner\sloops.
++D 2013-11-16T13:55:34.349
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 8a07bebafbfda0eb67728f4bd15a36201662d1a1
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -1139,7 -1139,7 +1139,8 @@@ F tool/vdbe-compress.tcl f12c884766bd14
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
  F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
- P cc17f1f05f15e9c62659a49c0656ff2b667bf701
- R b62a58b0c81de204f01fd6d52945fa47
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++P c7f2ed9f44be3b66a542ee42c0db63bab8ffd2db cee835fe902e46f283257fb8ec9d9744c7d6dd77
++R 9a08d5cf387c0a6debd995e2224a08b5
++T +closed cee835fe902e46f283257fb8ec9d9744c7d6dd77
  U drh
- Z 7ba076cecbcdde244db85dd719f20d67
 -Z d160133bb6592eb2691b4e35ce057d8a
++Z c4756f7866a605223b6628b959e50ab9

diff --cc manifest.uuid
index f80a0bc0b8b14b86f286fe7dfdaa2252cd0e9842,b556a77d1173b6868c7c3ce9771d2f2c52cdfd1b..bb971a575ab03cd7284d62857e9d49f78e48fabd
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- c7f2ed9f44be3b66a542ee42c0db63bab8ffd2db
 -cee835fe902e46f283257fb8ec9d9744c7d6dd77
++ee9353fdf3c8f19cd3c344ea8fb7c6d13cadd632