* MODULES.html.sh: Add to list of modules.
* lib/flock.c: flock implementation for Windows and Unix systems
which have fcntl.
* doc/glibc-functions/flock.texi: Update documentation.
* lib/sys_file.in.h: <sys/file.h> header file.
* m4/flock.m4: M4 macros.
* m4/sys_file_h.m4: M4 macros for replacement sys/file.h.
* modules/flock: flock module.
* modules/flock-tests: flock tests module.
* modules/sys_file: sys/file.h module.
* tests/test-flock.c: test suite for flock.