Update clang format file.

.clang-format

@@ -58,10 +58,12 @@ ForEachMacros:
   - BOOST_FOREACH
 IncludeBlocks:   Regroup
 IncludeCategories: 
-  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
-    Priority:        2
-  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
-    Priority:        3
+  - Regex:           '^(<windows.h>)'
+    Priority:        -3
+  - Regex:           '^("(win32|windows))'
+    Priority:        -2
+  - Regex:           '^(<.*)'
+    Priority:        -1
   - Regex:           '.*'
     Priority:        1
 IncludeIsMainRegex: '(Test)?$'