* winsup.h: Split out dtable definitions into separate header file.

* dtable.h: New file.
* sigproc.h: Eliminate pinfo.h usage here.  Use it in source files that need
it.

winsup/cygwin/mmap.cc

@@ -13,7 +13,8 @@ details. */
 #include <stddef.h>
 #include <sys/mman.h>
 #include <errno.h>
-
+#include "dtable.h"
+#include "pinfo.h"
 
 /*
  * Simple class used to keep a record of all current