Use the Kahan-Babushka-Neumaier algorithm to improve the accuracy of sum().

FossilOrigin-Name: c63e26e705f5e967e14ef6aea8ce226548293ad8d25066069f29fa89673913d2

diff --cc manifest
index 5aa49021d55c5acb246c9dac6f22a28e3993720a,4e20574abe25e39d57b526e19454ffc9537dcc4f..501658de52e023d35985db37c29561ebd74cb012
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Use\s"volatile"\sisntead\sof\s"#pragma"\sto\sget\sfloating\spoint\scalculations\nworking\scorrectly\swhen\scompiling\swith\sGCC\sfor\sx86\smachines.
- D 2023-07-06T00:55:06.161
 -C Fix\sminor\sinaccuracies\sin\sthe\snew\ssum()\salgorithm.
 -D 2023-07-06T14:45:53.235
++C Use\sthe\sKahan-Babushka-Neumaier\salgorithm\sto\simprove\sthe\saccuracy\sof\ssum().
++D 2023-07-06T15:44:38.951
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -2043,9 -2043,8 +2043,9 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 7b4c16731e7bf6f03f5adf4fcb2008c0b19be473fb1b90b405c217c08916586a 1d972a690fdc70ab40862bd38427d68b48e8802ddf8e5c301f2d58ce2178b6ec
- R edd6abc545b6b11f65503dd16b4a34c2
- T +closed 1d972a690fdc70ab40862bd38427d68b48e8802ddf8e5c301f2d58ce2178b6ec
 -P ebc5edd3b10c1102b07b9fb0d6837266b81e55504ef883b9b8a7ad5e8ab29dd2
++P 9427f42687ed6d97c474bf42d0c3e82d6f4b0075e74206adcb5699d72e32140e e3f7a960c9bd8e84cd70f0585bb955d043604a92001d0e2bf6c1216bb1fd7221
+ R fc07faedc8ec40abb250af878f96b89f
++T +closed e3f7a960c9bd8e84cd70f0585bb955d043604a92001d0e2bf6c1216bb1fd7221
  U drh
- Z 9d851cc5730e074609430b016c224723
 -Z a457302fb05d630d42e97f2453c1a24d
++Z d5a624e7df2c6f31ea17c42fd16ebd48
  # Remove this line to create a well-formed Fossil manifest.

diff --cc manifest.uuid
index 82d15a017280ed8f27d257e181452960b63a35ca,511e8e7930ce181be420a4f98dd4dfae742fb24a..abd1499c5d370bfaebf0a0baf042f80851f6a7fd
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 9427f42687ed6d97c474bf42d0c3e82d6f4b0075e74206adcb5699d72e32140e
 -e3f7a960c9bd8e84cd70f0585bb955d043604a92001d0e2bf6c1216bb1fd7221
++c63e26e705f5e967e14ef6aea8ce226548293ad8d25066069f29fa89673913d2