Now that Nick has finished off the last of the cleanups (hooray!), now
is likely the time to add -Werror to the build_warnings variable in
the various configure.ins.  These flags are only used when the user
explicitly passes --enable-build-warnings, so we can do this now that
we build cleanly with GCC with minimal disruption.

Okay for mainline?

bfd,binutils,gas,gprof,ld,opcodes/ChangeLog:

2005-02-16  Ben Elliston  <bje@au.ibm.com>

	* configure.in (build_warnings): Add -Werror.
	* configure: Rebuild.

The diffs for {bfd,binutils,gas,gprof,ld,opcodes}/configure.in are all
the same, so I'll paste in just one:

Index: configure.in
===================================================================
RCS file: /cvs/src/src/bfd/configure.in,v
retrieving revision 1.166
diff -u -p -c -r1.166 configure.in
*** configure.in	6 Jan 2005 16:18:20 -0000	1.166
--- configure.in	16 Feb 2005 00:14:02 -0000
*************** AC_ARG_WITH(mmap,
*** 51,57 ****
    *)    AC_MSG_ERROR(bad value ${withval} for BFD with-mmap option) ;;
  esac],[want_mmap=false])dnl
  
! build_warnings="-W -Wall -Wstrict-prototypes -Wmissing-prototypes"
  AC_ARG_ENABLE(build-warnings,
  [  --enable-build-warnings Enable build-time compiler warnings if gcc is used],
  [case "${enableval}" in
--- 51,57 ----
    *)    AC_MSG_ERROR(bad value ${withval} for BFD with-mmap option) ;;
  esac],[want_mmap=false])dnl
  
! build_warnings="-W -Wall -Wstrict-prototypes -Wmissing-prototypes -Werror"
  AC_ARG_ENABLE(build-warnings,
  [  --enable-build-warnings Enable build-time compiler warnings if gcc is used],
  [case "${enableval}" in