Try to push relevant WHERE clause terms of the outer query down

into the subquery in order to help the subquery run faster and/or
use less memory.   This is a cherry-pick of [6df18e949d36] with
bug fixes.

FossilOrigin-Name: cd6ac0784898609ddca887cfb87c042cf409acbbe4e4e84bc5bc1f8528de74fd

diff --cc manifest
index 8d0e566596ec4eac648a0035e77a08ec17127652,209c07afba1e9aa01b6cc932fed44e548e9db68b..0758b6353f7331943ff29ce9db9ed08fcc952d46
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\sthe\scovering\sindex\sOR\soptimization\s(check-in\s[fcbd6abd])\sso\sthat\nit\sworks\swith\sSQLITE_MAX_ATTACHED>30.\s\sBroken\sby\sa\sbad\scherry-pick\smerge.
- D 2017-07-08T01:01:08.062
 -C When\schecking\sfor\sthe\sWHERE-clause\spush-down\soptimization,\sverify\sthat\nall\sterms\sof\sthe\scompound\sinner\sSELECT\sare\snon-aggregate,\snot\sjust\sthe\nlast\sterm.\s\sFix\sfor\sticket\s[f7f8c97e97597].
 -D 2017-07-17T19:25:10.921
++C Try\sto\spush\srelevant\sWHERE\sclause\sterms\sof\sthe\souter\squery\sdown\ninto\sthe\ssubquery\sin\sorder\sto\shelp\sthe\ssubquery\srun\sfaster\sand/or\s\nuse\sless\smemory.\s\s\sThis\sis\sa\scherry-pick\sof\s[6df18e949d36]\swith\nbug\sfixes.
++D 2017-07-17T19:37:23.434
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 00d12636df7a5b08af09116bcd6c7bfd49b8b3b4
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -1250,7 -1250,8 +1250,8 @@@ F tool/vdbe_profile.tcl 67746953071a9f8
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P fcbd6abdb1a4cf622ff7e85625b9c2a9bbae92410359872924b7fc1e35046a75
- R e16d14bd52b65abae70b31af2e996886
 -P 52674f948c3e74e5cc32874d4885f2302ad1d5dd0bc45ff6bfda18cf4bea904a
 -Q +ec215f94ac9748c0acd82af0cc9e7a92249462f9
++P d227de8ad9cf757f30f5415ca8fccff3b5959621d09244bd1f444d3282c5b2ef adc082c1461e0237cd42653b529fbc136f5899baeff6ee32ee943d76184080c1
+ R a908a996bcff610704d1aca2821ce465
++T +closed adc082c1461e0237cd42653b529fbc136f5899baeff6ee32ee943d76184080c1
  U drh
- Z 1ba13c74fc4ad36a0d13cfbf7520225c
 -Z 30ce9b14a61bc1a1adc0dcec2dba7a8c
++Z 9d4148dec6ff72e63c10310b4326ef73

diff --cc manifest.uuid
index 2f2d4b0dd3e5a3d3defef9cf9ef686f25e52eba9,8b1424e5ae989b22f542e539c8b7ce31b6bd042f..b6d2b127f4c82c949ca03b5135a1ae7274a5dd60
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- d227de8ad9cf757f30f5415ca8fccff3b5959621d09244bd1f444d3282c5b2ef
 -adc082c1461e0237cd42653b529fbc136f5899baeff6ee32ee943d76184080c1
++cd6ac0784898609ddca887cfb87c042cf409acbbe4e4e84bc5bc1f8528de74fd