Revise C++ coding style using clang-format-6.0

Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`.  Use `clang-format` version 6.0.

* If you reached this commit for a line in `git blame`, re-run the blame
  operation starting at the parent of this commit to see older history
  for the content.

* See the parent commit for instructions to rebase a change across this
  style transition commit.

Tests/ModuleDefinition/example_mod_1.c

@@ -1,7 +1,7 @@
 #ifdef __WATCOMC__
-#define MODULE_CCONV __cdecl
+#  define MODULE_CCONV __cdecl
 #else
-#define MODULE_CCONV
+#  define MODULE_CCONV
 #endif
 
 int __declspec(dllimport) example_exe_function(void);