Merge the latest version of mutexfree-shmlock with this branch.

FossilOrigin-Name: 6007abfe0935a47edc90ef34a4f0a8c4263365b4e2e790e015a195be87c9f6b4

diff --cc manifest
index 2ecbf7cf20758e05350c3225d66bc6e0d6625ce4,16143f81693da9d7a6d60edca62642bbc0090326..096c746faf26c599de7c92f93b977e0cc6681bbc
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Avoid\sa\smutex\sin-and-out\sin\sunixShmBarrier()\son\sthis\sbranch.\sUse\n__sync_synchronize()\sinstead.
- D 2018-12-10T09:36:34.858
 -C Add\sextra\stests\sto\sshmlock.test\s(direct\stesting\sof\sxShmLock\smethods).
 -D 2018-12-10T15:51:05.281
++C Merge\sthe\slatest\sversion\sof\smutexfree-shmlock\swith\sthis\sbranch.
++D 2018-12-10T15:58:59.639
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F Makefile.in 68d0ba0f0b533d5bc84c78c13a6ce84ee81183a67014caa47a969e67f028fa1c
@@@ -495,12 -491,12 +495,12 @@@ F src/os.c 8aeb0b0f40f8f5b0da03fe497066
  F src/os.h 48388821692e87da174ea198bf96b1b2d9d83be5dfc908f673ee21fafbe0d432
  F src/os_common.h b2f4707a603e36811d9b1a13278bffd757857b85
  F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
- F src/os_unix.c 4cd8758cbd16ce1acc3559ff9cd5c78d7570e88076ef98b0d2601a75fee0146c
 -F src/os_unix.c 4b21c5148ca49fa136a6f404121080deee3e14f14ce07ea3cd132e15d40e5a93
++F src/os_unix.c 9bcd767c7d946ff46cdea7c108f5ae6b5cb5acc44e5bb723887b48ec7cac2f50
  F src/os_win.c 85d9e532d0444ab6c16d7431490c2e279e282aa0917b0e988996b1ae0de5c5a0
  F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 -F src/pager.c 75e0f3cfa3962c714f519f8a3d1e67ecca1c91de0e010a036b988e40ce9e4c73
 -F src/pager.h 217921e81eb5fe455caa5cda96061959706bcdd29ddb57166198645ef7822ac3
 -F src/parse.y 5cf85c2b9dfac38ac4e2bf2776484705186ce2eda8631e65cc0b04bf566c1173
 +F src/pager.c 79b8ced46a3c32be19ab4b00d8836292e460411d283a333cb008923c69fbca6a
 +F src/pager.h 389ba8f526d13026aa7081dc581aa742eb7207e3277e7106c522c5b65ad92590
 +F src/parse.y 9281e9941d5df0f7978c4bfe1521090ba7363ac4535c79f57531ba0194904d43
  F src/pcache.c 696a01f1a6370c1b50a09c15972bc3bee3333f8fcd1f2da8e9a76b1b062c59ee
  F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
  F src/pcache1.c ad0ffc5b35b0280d045ac569d34d4b842e3e6a4a118f6396b320987a0957afcc
@@@ -593,8 -589,8 +593,8 @@@ F src/vdbesort.c 90aad5a92608f2dd771c96
  F src/vdbetrace.c 79d6dbbc479267b255a7de8080eee6e729928a0ef93ed9b0bfa5618875b48392
  F src/vtab.c 70188a745dc4e57d26e942681ff4b2912b7c8249ad5de3f60f0677b4337bcfaa
  F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
- F src/wal.c 59b20f8fd0d7420e8896a1ef7cbd5db7352f383235ec25db08d9c22b55f4b603
 -F src/wal.c d1c4f4edd172d4b9320d785304bad3efc433baf672621653017434ab87f3f336
 -F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
++F src/wal.c 47e3230db60654d4d332ace2716fe16b99a8574189d80d6367c14f1dd3eb6ab5
 +F src/wal.h f325a5856b669f5ba449157485915816103857c8574efc746ac55eba3335c5e0
  F src/walker.c fb94aadc9099ff9c6506d0a8b88d51266005bcaa265403f3d7caf732a562eb66
  F src/where.c 3818e8a736a05d2cb194e64399af707e367fbcc5c251d785804d02eaf121288e
  F src/whereInt.h f125f29fca80890768e0b2caa14f95db74b2dacd3a122a168f97aa7b64d6968f
@@@ -1796,7 -1783,7 +1796,7 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 3aead209b4040c6c682fb892ee593219e52f766cd8da49bd7ad2994645e58433
- R bcc800104bf27a3aabac69060664e6d8
 -P d9157dd176a2d18c6e02a2a0c7e16cef2da43bf44be9765e0363f34aebad23e9
 -R 24f7a75900edcf030e0982b0e1c98eeb
++P 280d1a72dc269b4402853159949d7a905d414786074f5d80e951c9341ebbd1b5 d2c785f94cc6b704ce29147399e2c473fd0f4ff377f1379bd29178bf6d127c1a
++R f5b63cbe630ed07dd28689601501e2bf
  U dan
- Z eacacd23271d083db31c16e8c29f76f3
 -Z d8fb14bd354e885b5baff90283e91e8d
++Z e88a5887eab7167d6e9a36274f0b233f

diff --cc manifest.uuid
index a0a1ef7ace1bdc43a8636ef322e925e6afc0733a,abbf850327b13951a45d52a94b687ec0d8fc14b8..78ae18f769c56b4189f8ae8b0f117c1eefb2f89b
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 280d1a72dc269b4402853159949d7a905d414786074f5d80e951c9341ebbd1b5
 -d2c785f94cc6b704ce29147399e2c473fd0f4ff377f1379bd29178bf6d127c1a
++6007abfe0935a47edc90ef34a4f0a8c4263365b4e2e790e015a195be87c9f6b4

diff --cc src/os_unix.c
Simple merge

diff --cc src/wal.c
Simple merge