* winsup.h: Eliminate inclusion of most of the cygwin .h files. Use .h files

only in sources which require them.
* Makefile.in: Generate dependencies with -MD option.

winsup/cygwin/sync.cc

@@ -20,6 +20,7 @@ details. */
 #include <sys/wait.h>
 #include <errno.h>
 #include <stdlib.h>
+#include "sync.h"
 
 muto NO_COPY muto_start;