Revise include order using clang-format-6.0

Run the `clang-format.bash` script to update our C and C++ code to a new
include order `.clang-format`.  Use `clang-format` version 6.0.

Source/cmLocalUnixMakefileGenerator3.cxx

@@ -2,8 +2,6 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmLocalUnixMakefileGenerator3.h"
 
-#include "cmsys/FStream.hxx"
-#include "cmsys/Terminal.h"
 #include <algorithm>
 #include <cstdio>
 #include <sstream>
@@ -11,6 +9,9 @@
 
 #include <cm/memory>
 
+#include "cmsys/FStream.hxx"
+#include "cmsys/Terminal.h"
+
 #include "cmAlgorithms.h"
 #include "cmCustomCommand.h" // IWYU pragma: keep
 #include "cmCustomCommandGenerator.h"