Strive to use posix_fallocate() rather than ftruncate() when

posix_fallocate() is available.  Ticket [5eaa61ea18].

FossilOrigin-Name: 29980b08ec591f695386b715df72d4afb6ffc3fb

diff --cc manifest
index 028b6852d1b9d9207e60a61002e3942aca47f492,b522c75e004e1ecd4373ee2cc30c21cb88d3ca2b..ea35017ae91eb2eb6509d6653aafd51a3e724304
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Only\slog\sunlink()\serrors\sif\sthe\serror\sis\ssomething\sother\sthan\nSQLITE_IOERR_DELETE_NOENT.\s\sThe\serror\sis\sstill\sreported\sup\sthe\sstack,\sit\nis\ssimply\snot\sadded\sto\sthe\ssqlite3_log().
- D 2012-11-09T21:40:02.069
 -C Use\spreprocessor\smacros\sto\sautomatically\sdetect\swhether\sor\snot\nposix_allocate()\sis\savailable.\s\s(It\sis\sgenerally\savailable\son\sLinux\nbut\snot\son\sMac.)\s\sTicket\s[5eaa61ea1881040b17449ca043b6f8fd9ca55dc3]
 -D 2012-11-13T11:08:49.725
++C Strive\sto\suse\sposix_fallocate()\srather\sthan\sftruncate()\swhen\s\nposix_fallocate()\sis\savailable.\s\sTicket\s[5eaa61ea18].
++D 2012-11-13T11:16:04.644
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 82c41c0ed4cc94dd3cc7d498575b84c57c2c2384
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -1024,7 -1024,7 +1024,7 @@@ F tool/vdbe-compress.tcl f12c884766bd14
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
  F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
- P bed9c172ce624ab7b5b9de9ad42444891717ad9a
- R 6c7c8f8d3a3d00e4614865ddb6f518c4
 -P 356259617cfad04492a02912fdf781f54a2b4494
++P 5a3b07f0f5dfae7eea870303f52f37d6a17f1da2 597333f1024092b94bcd8772541e19a0f707bd40
+ R 1da6d6b008a37af0f12b5b83b4203af6
  U drh
- Z 81d94dfa08446549954e693bf8235ef9
 -Z 2b21d116614b6c7fcc6d8aed3f12096b
++Z 308917846cd590cd935ef45fbc502739

diff --cc manifest.uuid
index eae5c05106637886940585d3736beea127af7584,f7349a29f46e5f18e2cd389e6bcfc67c77f109e2..d6910efb93462e07ef6a9be686a6905b86fa93e7
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 5a3b07f0f5dfae7eea870303f52f37d6a17f1da2
 -597333f1024092b94bcd8772541e19a0f707bd40
++29980b08ec591f695386b715df72d4afb6ffc3fb