Remove unneeded header files from source files throughout.

winsup/cygwin/flock.cc

@@ -102,18 +102,14 @@
 #include "winsup.h"
 #include <assert.h>
 #include <sys/file.h>
-#include <fcntl.h>
 #include <unistd.h>
 #include <stdlib.h>
 #include "cygerrno.h"
-#include "perprocess.h"
 #include "security.h"
-#include "cygwin/version.h"
 #include "path.h"
 #include "fhandler.h"
 #include "dtable.h"
 #include "cygheap.h"
-#include "shared_info.h"
 #include "pinfo.h"
 #include "sigproc.h"
 #include "cygtls.h"