Update from Gnulib

This incorporates:
2019-05-24 flexmember: update comments
2019-05-18 pthread_sigmask: fix --enable-threads=windows compilation
2019-05-14 close-stream, closein, closeout: simplify
2019-05-09 verify: remove verify_true
2019-05-09 verify: support C2X and C++17 static_assert
* build-aux/config.guess, build-aux/config.sub:
* doc/misc/texinfo.tex, lib/flexmember.h, lib/verify.h:
* m4/flexmember.m4, m4/pthread_sigmask.m4:
Copy from Gnulib
* m4/gnulib-comp.m4: Regenerate.

2019-05-26  Paul Eggert  <eggert@cs.ucla.edu>

Update author/maintainer info
This mostly updates email addresses and fixes spellings of
author and maintainer names.

1 files changed, 14 insertions, 3 deletions

diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index ccd112941ac..53f2fc4835b 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2019-04-12.13}
+\def\texinfoversion{2019-05-18.15}
 %
 % Copyright 1985, 1986, 1988, 1990-2019 Free Software Foundation, Inc.
 %
@@ -4952,6 +4952,8 @@ end
   \definedummyword\sup
   \definedummyword\textdegree
   %
+  \definedummyword\subentry
+  %
   % We want to disable all macros so that they are not expanded by \write.
   \macrolist
   \let\value\dummyvalue
@@ -5224,10 +5226,10 @@ end
 }
 
 \def\indexwriteseealso#1{
-  \gdef\pagenumbertext{@seealso{#1}}%
+  \gdef\pagenumbertext{\string\seealso{#1}}%
 }
 \def\indexwriteseeentry#1{
-  \gdef\pagenumbertext{@seeentry{#1}}%
+  \gdef\pagenumbertext{\string\seeentry{#1}}%
 }
 
 % The default definitions
@@ -5315,6 +5317,15 @@ end
 % the current value of \escapechar.
 \def\escapeisbackslash{\escapechar=`\\}
 
+% Use \ in index files by default.  texi2dvi didn't support @ as as the escape 
+% character (as it checked for "\entry" in the files, and not "@entry").  When 
+% the new version of texi2dvi has had a chance to become more prevalent, then 
+% the escape character can change back to @ again.  This should be an easy 
+% change to make now because both @ and \ are only used as escape characters in 
+% index files, never standing for themselves. 
+%
+\set txiindexescapeisbackslash
+
 % Write the entry in \indextext to the index file.
 %
 \def\doindwrite{%