Merge latest mutexfree-shmlock changes into this branch.

FossilOrigin-Name: 186b376ec3713f9c8a1499a9675b3c1b42ef3a123848506a48d3a196ba6461f3

diff --cc manifest
index 096c746faf26c599de7c92f93b977e0cc6681bbc,2f7fef6936271fb4f15f2d9ef19b0fde041f5a3c..63d7417ff54505de7d3e6e06d9d71f93a71b5574
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Merge\sthe\slatest\sversion\sof\smutexfree-shmlock\swith\sthis\sbranch.
- D 2018-12-10T15:58:59.639
 -C Make\sSQLITE_MFS_NSHARD\sa\scompile\stime\ssetting.
 -D 2018-12-10T16:52:31.796
++C Merge\slatest\smutexfree-shmlock\schanges\sinto\sthis\sbranch.
++D 2018-12-10T16:53:32.838
  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 9bcd767c7d946ff46cdea7c108f5ae6b5cb5acc44e5bb723887b48ec7cac2f50
 -F src/os_unix.c e191348d66fcbcf137cb2497de2c1e2ccca3caac0515a42c1a1d38043f519e9e
++F src/os_unix.c 177e5490d3a3c702fac87ff6dd183b56a24fb5fabe76841c3bf8a03ad85ff43b
  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
@@@ -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 280d1a72dc269b4402853159949d7a905d414786074f5d80e951c9341ebbd1b5 d2c785f94cc6b704ce29147399e2c473fd0f4ff377f1379bd29178bf6d127c1a
- R f5b63cbe630ed07dd28689601501e2bf
 -P d2c785f94cc6b704ce29147399e2c473fd0f4ff377f1379bd29178bf6d127c1a
 -R 405c2e0a847d1dc9742f041e349c6a79
++P 6007abfe0935a47edc90ef34a4f0a8c4263365b4e2e790e015a195be87c9f6b4 b9a741519055a8560ec1d0ab7d0c15ff8db53e740011825506cd2ede11c956f0
++R 0d4f69b7321e017a524ef7e6c799dc7e
  U dan
- Z e88a5887eab7167d6e9a36274f0b233f
 -Z 0d67b443d35d0a267898c50a3a55aea3
++Z 7b310a2bc179bf5031c1fdfa8fe699cc

diff --cc manifest.uuid
index 78ae18f769c56b4189f8ae8b0f117c1eefb2f89b,890ad2c80ff81aa5f7e051d8826521566f51454a..06123c5a6252dda4af003601ec5560974c213430
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 6007abfe0935a47edc90ef34a4f0a8c4263365b4e2e790e015a195be87c9f6b4
 -b9a741519055a8560ec1d0ab7d0c15ff8db53e740011825506cd2ede11c956f0
++186b376ec3713f9c8a1499a9675b3c1b42ef3a123848506a48d3a196ba6461f3

diff --cc src/os_unix.c
Simple merge