Run clang-format on all files

The main change here is to reorder headers.

src/builtin_printf.h

@@ -2,9 +2,8 @@
 #ifndef FISH_BUILTIN_PRINTF_H
 #define FISH_BUILTIN_PRINTF_H
 
-#include <cwchar>
-
 #include <cstring>
+#include <cwchar>
 
 class parser_t;