gnulib: update.
build: simplify and improve the compiler warnings for tests.

* configure.ac (warn_common, warn_c, warn_cxx): New.
Use them to compute independently the options supported
by the C and C++ compilers.
Don't AC_SUBST the variables passed to gl_WARN_ADD: it
does it for us.
(WARN_CFLAGS_TEST, WARN_CXXFLAGS_TEST): Don't aggregate
$WARN_CFLAGS and $WARN_CXXFLAGS in them now, leave it
to atlocal.in.
(O0CFLAGS, O0CXXFLAGS): Move their definition to...
* tests/atlocal.in: here.
Be more systematic between C and C++.
Reorder to factor between variables.
Propagate all of the variables when --compile-c-with-cxx.
c++: use nullptr for C++11.

C++11 introduces "nullptr" which plays the role of C's NULL, in
replacement of "0".  Fix the C++ skeletons to avoid warnings about
uses of "0" in place of "nullptr", and improve C skeletons to also use
this "nullptr" when compiled with a C++11 compiler.

* configure.ac: More C++ warnings.
* NEWS (2.5.1): Document this.
* data/c++.m4, data/c.m4 (b4_null_define): New.
(b4_null): Use YY_NULL instead of 0.
* data/glr.c, data/lalr1.cc, data/location.cc, data/yacc.c:
Call b4_null_define/b4_null where appropriate.
Use YY_NULL instead of NULL.
* data/location.cc (initialize): Accept a default argument,
YY_NULL.
* tests/actions.at, tests/calc.at: Adjust.

* data/glr.c, lib/libiberty.h, src/system.h (__attribute__):
Do not disable it when __STRICT_ANSI__ is defined, as, for
instance, it disables the __attribute__((unused)) which
protects us from some compiler warnings.
This was already done elsewhere in Bison, in 2001, see
4a0d89369599a2cea01f4fbdf791f426a02cb5a3.
* tests/regression.at: Adjust output.
glr: do not use locations when they are not requested

When the test suite runs with -O2 and warnings enabled, G++
complains of locations being used, but not initialized.
The simplest is to not use locations.

* data/glr.c (b4_locuser_formals, b4_locuser_args): New.
Use them when locations should not be used.
Use b4_locations_if where appropriate.
(yyuserAction): Modify the order to the arguments to make
it more alike the other routines, and to make use of
b4_locuser_args simpler.
c++: locations: remove useless "inline".

* data/location.cc: "inline" is implicit when defining
methods in the class definition.
c++: locations: provide convenience constructors.

* data/location.cc (position::position): Accept file, line and
column as arguments with default values.
Always qualify initial line and column literals as unsigned.
(location::location): Provide convenience constructors.
(cherry picked from commit 0634493cdde92cbdb8d9fb95a5bebe596bb53798)

Conflicts:

	ChangeLog-2012
	data/location.cc
doc: c++: complete the location documentation.

* data/location.cc (position::initialize, location::initialize):
Also accept line and column, with default values.
* doc/bison.texinfo (C++ position, C++ location): New nodes.
Describe more thoroughly these classes.
Fix several Texinfo misuses.
build: remove ancient Autoconf tests.

lib/subpipe.c was removed in 47fa574761319b0a422691223c9b8a9a72f36aa2.

* m4/subpipe.m4: Remove.
* configure.ac (BISON_PREREQ_SUBPIPE): Remove.
bump to 2012 in skeletons.

* data/glr.c, data/glr.cc, data/lalr1.cc, data/lalr1.java,
* data/location.cc, data/yacc.c: Bump copyright year ranges.
Merge remote-tracking branch 'origin/maint'

* origin/maint:
  bump to 2012 in skeletons.
  build: remove ancient Autoconf tests.
  doc: c++: complete the location documentation.
  c++: locations: provide convenience constructors.
  c++: locations: remove useless "inline".
  glr: do not use locations when they are not requested
  c++: use nullptr for C++11.
  build: simplify and improve the compiler warnings for tests.
  gnulib: update.
  maint: formatting changes.
  NEWS: update.
  Java: Fix syntax error handling without error token.
  tests: beware of -pedantic on large #line numbers.
  tests: when using the C++ compiler, use its flags too.

Conflicts:
	data/glr.c
	data/glr.cc
	data/lalr1.cc
	data/location.cc
	data/yacc.c
	tests/Makefile.am
c++: more YY_NULL

Caught by maintainer-check-g++.
* data/glr.c, data/lalr1.cc, data/yacc.c, tests/cxx-type.at,
* tests/glr-regression.at, tests/push.at:
When simple to do, avoid expliciting the null ptr.
Otherwise use YY_NULL.
c++: more YY_NULL

Caught by maintainer-check-g++.
* data/glr.c, data/lalr1.cc, data/yacc.c, tests/cxx-type.at,
* tests/glr-regression.at, tests/push.at:
When simple to do, avoid expliciting the null ptr.
Otherwise use YY_NULL.
(cherry picked from commit eeaf1dc646048e464d97f6a572b8894632e6e47a)

Conflicts:

	data/glr.c
	data/lalr1.cc
	tests/cxx-type.at
Fix Doxygen comment.

* src/InadequacyList.h: s#</t>#</tt>#.
Fix Doxygen generation and clean-up.

* doc/Doxyfile.in: Amend OUTPUT_DIRECTORY.
* doc/local.mk (html-local): Amend working directory.
(CLEANDIRS): Fix "html", remove "latex".
doc: help Doxygen find our files.

* doc/Doxyfile.in (INCLUDE_PATH): here.
doc: upgrade Doxyfile.

* doc/Doxyfile.in: Run doxygen -u.
Prompted by Tim Landscheidt.
build: don't rely on $< in non-pattern rules.

* doc/local.mk, tests/local.mk: here.
Reported by Stefano Lattarini.
build: fix distcheck issues.

For some reason it seems that texi2dvi -o no longer forces --clean
mode, so we have stray TeX compilation files staying in top_builddir
since TeX is run from there.

While at it, upgrade the generation of the (completely obsolete)
reference card.  Target PDF.

* doc/local.mk (TEXI2DVI): Pass --build-dir.
(CLEANDIRS): More accurate.
(doc/refcard.dvi): Replace with...
(doc/refcard.pdf): this.
Adjust dependencies.
doc: fix documentation of YYERROR.

* doc/bison.texinfo (Table of Symbols): Fix the documentation
of YYERROR by copying that from "Action Features".
doc: fix index.

http://lists.gnu.org/archive/html/bison-patches/2012-04/msg00006.html

* doc/bison.texinfo: Avoid using @def* variant with more
than the defined entity as main entity, as it results in
an incorrect index.  For instance, don't document
{return YYERROR;}, which results in a single index entry
"return YYERROR;", but rather as typed function whose
return type is "type", and whose argument list is ";".