Merge remote-tracking branch 'origin/maint'

* origin/maint:
  maint: update gnu-web-doc-update.
  maint: post-release administrivia
  version 2.6
  maint: prepare for release 2.6
  maint: post-release administrivia
  version 2.5.91
  maint: prepare NEWS.
  maint: fix spaces.
  tests: adjust to case where the C compiler is actually a C++ compiler
  tests: fix dependencies
  doc: fix Texinfo command
  maint: Valgrind on OS X.
  tests: be sure that backups are safe.
  maint: dead comment.
  tests: refactor for legibility.
  tests: refactor the bison invocations.
  maint: fix syntax-check ignore patterns.
  gnulib: update
  gnulib: update.
  gnulib: update

Conflicts:
	build-aux/Makefile.am
	cfg.mk
	tests/Makefile.am

cfg.mk

@@ -54,7 +54,8 @@ update-copyright: update-b4-copyright update-package-copyright-year
 update-copyright-env = \
   UPDATE_COPYRIGHT_FORCE=1 UPDATE_COPYRIGHT_USE_INTERVALS=1
 
-exclude = $(foreach a,$(1),$(eval exclude_file_name_regexp--sc_$(a)))
+exclude = \
+  $(foreach a,$(1),$(eval $(subst $$,$$$$,exclude_file_name_regexp--sc_$(a))))
 $(call exclude,								\
   bindtextdomain=^lib/main.c$$						\
   program_name=^lib/main.c$$						\
@@ -62,6 +63,7 @@ $(call exclude,								\
   prohibit_always-defined_macros+=?|^lib/timevar.c$$			\
   prohibit_always-defined_macros+=?|^src/(parse-gram.c|system.h)$$	\
   prohibit_always-defined_macros+=?|^tests/regression.at$$		\
+  prohibit_defined_have_decl_tests=?|^lib/timevar.c$$			\
   prohibit_empty_lines_at_EOF=^src/parse-gram.h$$			\
   prohibit_strcmp=^doc/bison\.texi$$					\
   require_config_h_first=^(lib/yyerror|data/(glr|yacc))\.c$$		\