Update Acknowledgments sections

* doc/emacs/ack.texi (Acknowledgments):
* doc/emacs/emacs.texi (Acknowledgments): Update for Emacs 27.

doc/emacs/ack.texi

@@ -235,6 +235,12 @@ use it, Snake and Tetris.
 Andrew Cohen wrote @file{spam-wash.el}, to decode and clean email before
 it is analyzed for spam.
 
+@item
+Daniel Colascione wrote the portable dumping code in @file{pdumper.c}
+and elsewhere.  He also implemented double-buffering for X-based GUI
+frames, and the original support for loading shared-object modules
+into Emacs.
+
 @item
 Theresa O'Connor wrote @file{json.el}, a file for parsing and
 generating JSON files.
@@ -502,6 +508,10 @@ expansion package.
 Tassilo Horn wrote DocView mode, allowing viewing of PDF, PostScript and
 DVI documents.
 
+@item
+Khaled Hosny, Yamamoto Mitsuharu, and Eli Zaretskii implemented
+text shaping with HarfBuzz for Emacs.
+
 @item
 Joakim Hove wrote @file{html2text.el}, a html to plain text converter.
 
@@ -702,7 +712,9 @@ files.
 Juri Linkov wrote @file{misearch.el}, extending isearch to multi-buffer
 searches; the code in @file{files-x.el} for handling file- and
 directory-local variables; and the @code{info-finder} feature that
-creates a virtual Info manual of package keywords.
+creates a virtual Info manual of package keywords.  He also
+implemented the Tab Bar and window tab-lines, and added numerous
+enhancements and improvements in I-search.
 
 @item
 Leo Liu wrote @file{pcmpl-x.el}, providing completion for
@@ -817,6 +829,11 @@ David Megginson wrote @file{derived.el}, which allows one to define new
 major modes by inheriting key bindings and commands from existing major
 modes.
 
+@item
+Jimmy Aguilar Mena wrote the code to support the @code{:extend} face
+attribute, and also implemented the optional
+@code{display-fill-column-indicator} feature.
+
 @item
 Will Mengarini wrote @file{repeat.el}, a command to repeat the preceding
 command with its arguments.
@@ -1083,6 +1100,10 @@ Wolfgang Rupprecht wrote Emacs 19's floating-point support (including
 Kevin Ryde wrote @file{info-xref.el}, a library for checking
 references in Info files.
 
+@item
+Phil Sainty wrote @file{so-long.el}, a set of features for easier
+editing of files with very long lines.
+
 @item
 James B. Salem and Brewster Kahle wrote @file{completion.el}, providing
 dynamic word completion.
@@ -1234,6 +1255,10 @@ buffers.
 Tibor Šimko and Milan Zamazal wrote @file{slovak.el}, support for
 editing text in Slovak language.
 
+@item
+João Távora wrote many improvements for @file{flymake.el}, an
+on-the-fly syntax-checking package.
+
 @item
 Luc Teirlinck wrote @file{help-at-pt.el}, providing local help through
 the keyboard.

doc/emacs/emacs.texi

@@ -1404,6 +1404,7 @@ Berry, Anna M. Bigatti, Ray Blaak, Martin Blais, Jim Blandy, Johan
 Bockgård, Jan Böcker, Joel Boehland, Lennart Borgman, Per Bothner,
 Terrence Brannon, Frank Bresz, Peter Breton, Emmanuel Briot, Kevin
 Broadey, Vincent Broman, Michael Brouwer, David M. Brown, Ken Brown, Stefan Bruda,
+Daniel Colascione,
 Georges Brun-Cottan, Joe Buehler, Scott Byer, Włodek Bzyl, Tino Calancha,
 Bill Carpenter, Per Cederqvist, Hans Chalupsky, Chris Chase, Bob
 Chassell, Andrew Choi, Chong Yidong, Sacha Chua, Stewart Clamen, James
@@ -1429,7 +1430,7 @@ Guillaume, Dmitry Gutov, Doug Gwyn, Bruno Haible, Ken'ichi Handa, Lars Hansen, C
 Hanson, Jesper Harder, Alexandru Harsanyi, K. Shane Hartman, John
 Heidemann, Jon K. Hellan, Magnus Henoch, Markus Heritsch, Dirk
 Herrmann, Karl Heuer, Manabu Higashida, Konrad Hinsen, Anders Holst,
-Jeffrey C. Honig, Tassilo Horn, Kurt Hornik, Tom Houlder, Joakim
+Jeffrey C. Honig, Tassilo Horn, Kurt Hornik, Khaled Hosny, Tom Houlder, Joakim
 Hove, Denis Howe, Lars Ingebrigtsen, Andrew Innes, Seiichiro Inoue,
 Philip Jackson, Martyn Jago, Pavel Janik, Paul Jarc, Ulf Jasper,
 Thorsten Jolitz, Michael K. Johnson, Kyle Jones, Terry Jones, Simon
@@ -1449,7 +1450,7 @@ Lüdecke, Greg McGary, Roland McGrath, Michael McNamara, Alan Mackenzie,
 Christopher J. Madsen, Neil M. Mager, Artur Malabarba, Ken Manheimer, Bill Mann,
 Brian Marick, Simon Marshall, Bengt Martensson, Charlie Martin,
 Yukihiro Matsumoto, Tomohiro Matsuyama, David Maus, Thomas May, Will Mengarini, David
-Megginson, Stefan Merten, Ben A. Mesander, Wayne Mesard, Brad
+Megginson, Jimmy Aguilar Mena, Stefan Merten, Ben A. Mesander, Wayne Mesard, Brad
 Miller, Lawrence Mitchell, Richard Mlynarik, Gerd Möllmann, Dani Moncayo, Stefan
 Monnier, Keith Moore, Jan Moringen, Morioka Tomohiko, Glenn Morris,
 Don Morrison, Diane Murray, Riccardo Murri, Sen Nagata, Erik Naggum,
@@ -1468,7 +1469,7 @@ Reitter, Alex Rezinsky, Rob Riepel, Lara Rios, Adrian Robert, Nick
 Roberts, Roland B. Roberts, John Robinson, Denis B. Roegel, Danny
 Roozendaal, Sebastian Rose, William Rosenblatt, Markus Rost, Guillermo
 J. Rozas, Martin Rudalics, Ivar Rummelhoff, Jason Rumney, Wolfgang
-Rupprecht, Benjamin Rutt, Kevin Ryde, James B. Salem, Masahiko Sato,
+Rupprecht, Benjamin Rutt, Kevin Ryde, Phil Sainty, James B. Salem, Masahiko Sato,
 Timo Savola, Jorgen Schäfer, Holger Schauer, William Schelter, Ralph
 Schleicher, Gregor Schmid, Michael Schmidt, Ronald S. Schnell,
 Philippe Schnoebelen, Jan Schormann, Alex Schroeder, Stefan Schoef,
@@ -1481,9 +1482,9 @@ South, Andre Spiegel, Michael Staats, Thomas Steffen, Ulf Stegemann,
 Reiner Steib, Sam Steingold, Ake Stenhoff, Philipp Stephani, Peter Stephenson, Ken
 Stevens, Andy Stewart, Jonathan Stigelman, Martin Stjernholm, Kim F.
 Storm, Steve Strassmann, Christopher Suckling, Olaf Sylvester, Naoto
-Takahashi, Steven Tamm, Jan Tatarik, Luc Teirlinck, Jean-Philippe Theberge, Jens
+Takahashi, Steven Tamm, Jan Tatarik, João Távora, Luc Teirlinck,
-T. Berger Thielemann, Spencer Thomas, Jim Thompson, Toru Tomabechi,
+Jean-Philippe Theberge, Jens T.@: Berger Thielemann, Spencer Thomas,
-David O'Toole, Markus Triska, Tom Tromey, Eli
+Jim Thompson, Toru Tomabechi, David O'Toole, Markus Triska, Tom Tromey, Eli
 Tziperman, Daiki Ueno, Masanobu Umeda, Rajesh Vaidheeswarran, Neil
 W. Van Dyke, Didier Verna, Joakim Verona, Ulrik Vieth, Geoffrey
 Voelker, Johan Vromans, Inge Wallin, John Paul Wallington, Colin