This incorporates:
2020-06-28 getrandom: do not depend on ‘open’ on mingw
2020-06-28 getrandom: fix compilation errors on older versions of mingw
* build-aux/config.sub, lib/getrandom.c, m4/getrandom.m4:
Copy from Gnulib
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

This incorporates:
2020-06-27 getloadavg: don’t depend on fopen-gnu
2020-06-25 c-dtoastr, c-ldtoastr: new modules
2020-06-01 getloadavg: fix double-increment bug
2020-06-01 tempname: use getrandom, not getentropy
2020-05-31 tempname: merge from glibc and coreutils
2020-05-31 getentropy: work around a macOS and Solaris problem
2020-05-31 fnmatch: merge from glibc
2020-05-30 unistd: remove conflicting declaration of getrandom
2020-05-30 don't assume that UNICODE is not defined
2020-05-29 fix compilation error on native Windows
2020-05-28 avoid dynamic loading of Windows API functions when possible
2020-05-28 at-internal: make more robust in multithreaded applications
2020-05-28 getloadavg: make more robust in multithreaded applications
2020-05-27 getloadavg: make more robust in multithreaded applications
2020-05-26 count-one-bits: fix MSVC specific code
2020-05-25 getentropy, getrandom: new modules
2020-05-24 open, openat: really support O_CLOEXEC
2020-05-23 verify: document ‘assume’ better
2020-05-21 regex: configure better with "clang -fsanitize=leak"
2020-05-21 memmem: configure better with "clang -fsanitize=undefined"
2020-05-19 ftoastr: fix ifndef typo
* build-aux/config.guess, build-aux/config.sub, doc/misc/texinfo.tex:
* lib/count-one-bits.h, lib/ftoastr.c, lib/ftoastr.h:
* lib/getloadavg.c, lib/gettimeofday.c, lib/libc-config.h:
* lib/open.c, lib/openat-proc.c, lib/tempname.c, lib/tempname.h:
* lib/unistd.in.h, lib/verify.h, m4/memmem.m4, m4/regex.m4:
* m4/unistd_h.m4:
Update from Gnulib.
* lib/getrandom.c, lib/sys_random.in.h:
* m4/getrandom.m4, m4/sys_random_h.m4:
New files, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

This incorporates:
2020-05-11 careadlinkat: fix GCC 10 workaround
2020-05-10 careadlinkat: limit GCC workaround
2020-05-10 attribute: clarify list of attributes
2020-05-10 string: fix compilation error in C++ mode
2020-05-09 manywarnings: port to GCC 10.1
2020-05-09 careadlinkat: pacify -Wreturn-local-addr
2020-05-09 attribute: remove ATTRIBUTE_DEPRECATED
2020-05-09 attribute: Add comments
* lib/attribute.h, lib/careadlinkat.c, lib/string.in.h:
* lib/warn-on-use.h, m4/manywarnings.m4: Copy from Gnulib.

This incorporates:
2020-05-09 stdio: don't redefine _GL_ATTRIBUTE_FORMAT
2020-05-09 dirent, stdlib, string: don't redefine _GL_ATTRIBUTE_PURE
2020-05-08 limits-h: define LONG_BIT correctly on Haiku/x86_64
2020-05-08 ignore-value tests: use module 'attribute'
2020-05-06 attribute: minor style fixes
* build-aux/config.sub, doc/misc/texinfo.tex, lib/attribute.h:
* lib/dirent.in.h, lib/limits.in.h, lib/stdio.in.h, lib/stdlib.in.h:
* lib/string.in.h, m4/gnulib-common.m4:
Copy from Gnulib.

This incorporates:
2020-05-03 attribute: new module
2020-04-13 explicit_bzero: improve code style
2020-04-13 explicit_bzero: On native Windows, use SecureZeroMemory
2020-04-13 explicit_bzero: use memset_s() when available
2020-04-04 maint: remove a stray inter-word space
* build-aux/config.guess, build-aux/config.sub:
* build-aux/gitlog-to-changelog, build-aux/update-copyright:
* doc/misc/texinfo.tex, lib/explicit_bzero.c, lib/ieee754.in.h:
* lib/nstrftime.c, m4/explicit_bzero.m4, m4/gnulib-common.m4:
Copy from Gnulib.
* lib/attribute.h: New file, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

05089a4d65 (origin/emacs-27) Tweak wording re constant variables
a1040861f1 Tweak setcar-related wording
751510f865 * lisp/image-mode.el: Add prefix key 's' and reduce depend...
9261a219ec * doc/emacs/windows.texi (Window Convenience): Decribe mor...
e1d42da0d6 Fix mutability glitches reported by Drew Adams
5805df74f5 Improve mutability doc
dca35b31d0 Improve mutability documentation
81e7d7f111 Document that quoting yields constants
5734339f40 * doc/lispref/keymaps.texi (Extended Menu Items, Easy Menu...
14a570afae Remove #' and function quoting from lambda forms in manual
d5ec18c66b * src/regex-emacs.c (re_match_2_internal): Rework comment ...
4df8a61117 Add new node "Image Mode" to Emacs Manual.
d7d5ee6c57 ; Fix a typo in cmdargs.texi (bug#40701)
5e9db48fbe * doc/lispref/display.texi (Customizing Bitmaps): Fix typo.
eebfb72c90 Document constant vs mutable objects better
6c187ed6b0 Improve documentation of 'sort-lines'
52288f4b66 Mention 'spam-stat-process-directory-age' in the documenta...
067b070598 ; Fix some typos and doc issues (bug#40695)

# Conflicts:
#	etc/NEWS

Code is supposed to use the filename module now.
* admin/merge-gnulib (GNULIB_MODULES): Replace dosname with filename.
* lib/dosname.h: Remove this forwarding stub.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib-src/emacsclient.c, src/fileio.c:
Include filename.h instead of dosname.h.

This incorporates:
2020-03-28 Use module 'filename' instead of module 'dosname'
2020-03-28 dosname: Redirect to 'filename'
* lib/at-func.c, lib/canonicalize-lgpl.c, lib/dosname.h:
Copy from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/filename.h: New file, copied from Gnulib.

This incorporates:
2020-03-25 getopt-posix: port __GETOPT_PREFIX to macOS
2020-03-22 acl-permissions: Improve autoconf macro
* lib/getopt-pfx-core.h, m4/acl.m4: Copy from Gnulib.