Enhancements to the SQLITE_ENABLE_SETLK_TIMEOUT compile-time option to avoid

rare deadlocks on recovery.

FossilOrigin-Name: 06885e9aa4e430d10f4b32105bcf405c65fd6f7b4cd451baf56fb4f12f408963

diff --cc manifest
index 948392dc01b4ae914728627b9b2b645fc2c3f018,5a774946b584b7a6569fe1d00a17003706fb07e1..8369e9b1b068fd6e1d18e8868663c4673920811e
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C MSVC\sdoes\snot\sallow\sconstant\sexpressions\sas\sinitializers\sfor\nconstants\swith\s/fp:strict.
- D 2020-03-28T12:01:25.479
 -C Modifications\sto\sthe\sway\sblocking\slocks\sare\sused\sin\sSQLITE_ENABLE_SETLK_TIMEOUT\sbuilds\sso\sthat\smultiple\sprocesses\sor\sthreads\smay\snot\sdeadlock\swhen\soperating\son\sa\ssingle\sdatabase.
 -D 2020-03-27T17:23:17.566
++C Enhancements\sto\sthe\sSQLITE_ENABLE_SETLK_TIMEOUT\scompile-time\soption\sto\savoid\nrare\sdeadlocks\son\srecovery.
++D 2020-03-28T19:02:39.828
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -1860,7 -1860,10 +1860,8 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
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  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
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- R 46546f10d10bf6eae2668583a26e4118
 -R 9bc9d6a926251e677cf43f4b2b436987
 -T *branch * setlk-deadlock-fix
 -T *sym-setlk-deadlock-fix *
 -T -sym-trunk *
 -U dan
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++P 076658e5d21d9284448f41312b83a6c3d25394c2bfa088ef6cdfe1dc60277856 c516027d5fd876b7d0bf566435667d554db29ded30ad6fc1165caa4a93d015a0
++R fb7b5ba8a8e597ba045f062237a1d909
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 +U drh
- Z bff83d42b371b917e696cd55828e7b1b
++Z 0010a8489027f8740d0c36f8296e432b

diff --cc manifest.uuid
index 66904f191eb44cee0f280c9b109412c77ac7b244,461b87b10ab6808c9163925f7afca085d917cc9b..156bd9418c7f77b70cde67979de32aea53f85355
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 076658e5d21d9284448f41312b83a6c3d25394c2bfa088ef6cdfe1dc60277856
 -c516027d5fd876b7d0bf566435667d554db29ded30ad6fc1165caa4a93d015a0
++06885e9aa4e430d10f4b32105bcf405c65fd6f7b4cd451baf56fb4f12f408963