master updated (3480071 -> f633e01)

[Glenn Morris]

gm pushed a change to branch master.

      from  3480071   Fix C-h C-h bug due to mutating a hash key
      adds  d1e8ce8   Make after-change-functions called from call-process get 
the correct BEG
      adds  9f6a4bb   Remove the optional KEEP-ORDER argument to regexp-opt
      adds  4d8d25d   * doc/lispref/variables.texi (special-variable-p): 
Clarify limits
      adds  75a9eee   ; * src/editfns.c (Fbuffer_size): Tiny clarification.
      adds  78d76cd   Remove redundant 'msft' compilation error rule (bug#39595)
      adds  faada7c   Remove obsolete menu entry "Redisplay buffer"
      adds  7448834   Correct default regexp in 'package-menu-hide-package'
      adds  b392c9f   Fix 'reverse-region' when less than one line is in region
      adds  888ffd9   Fix unexec failure on macOS 10.15.4
      adds  7ceb45f   Reformulate c-end-of-macro, handling multiline block 
comments better
       new  f633e01   Merge from origin/emacs-27


Summary of changes:
 doc/lispref/searching.texi               |  9 ++---
 doc/lispref/variables.texi               |  4 +++
 etc/NEWS.27                              |  7 ----
 lisp/emacs-lisp/package.el               |  6 ++--
 lisp/emacs-lisp/regexp-opt.el            | 43 +++++------------------
 lisp/progmodes/cc-engine.el              | 58 +++++++++++++++-----------------
 lisp/progmodes/cc-langs.el               | 36 ++++++--------------
 lisp/progmodes/compile.el                |  7 ----
 lisp/sort.el                             | 17 +++++++---
 src/callproc.c                           |  5 +--
 src/editfns.c                            |  2 +-
 src/unexmacosx.c                         | 47 +++++++++++++-------------
 test/lisp/emacs-lisp/regexp-opt-tests.el | 44 ++++--------------------
 13 files changed, 104 insertions(+), 181 deletions(-)