Deprecate a.out support for NetBSD targets.

As discussed previously, a.out support is now quite deprecated, and in
some cases removed, in both Binutils itself and NetBSD, so this legacy
default makes little sense. `netbsdelf*` and `netbsdaout*` still work
allowing the user to be explicit about there choice. Additionally, the
configure script warns about the change as Nick Clifton requested.

One possible concern was the status of NetBSD on NS32K, where only a.out
was supported. But per [1] NetBSD has removed support, and if it were to
come back, it would be with ELF. The binutils implementation is
therefore marked obsolete, per the instructions in the last message.

With that patch and this one applied, I have confirmed the following:

--target=i686-unknown-netbsd
--target=i686-unknown-netbsdelf
  builds completely

--target=i686-unknown-netbsdaout
  properly fails because target is deprecated.

--target=vax-unknown-netbsdaout builds completely except for gas, where
the target is deprecated.

[1]: https://mail-index.netbsd.org/tech-toolchain/2021/07/19/msg004025.html
---
 bfd/config.bfd                             | 43 +++++++++++++--------
 bfd/configure.ac                           |  5 +--
 binutils/testsuite/binutils-all/nm.exp     |  2 +-
 binutils/testsuite/lib/binutils-common.exp |  7 +---
 config/picflag.m4                          |  4 +-
 gas/configure.tgt                          |  9 +++--
 gas/testsuite/gas/arm/blx-bl-convert.d     |  2 +-
 gas/testsuite/gas/arm/blx-local-thumb.d    |  2 +-
 gas/testsuite/gas/sh/basic.exp             |  2 +-
 gdb/configure.host                         | 34 +++++++----------
 gdb/configure.tgt                          |  2 +-
 gdb/testsuite/gdb.asm/asm-source.exp       |  6 +--
 intl/configure                             |  2 +-
 ld/configure.tgt                           | 44 +++++++++++-----------
 ld/testsuite/ld-arm/arm-elf.exp            |  4 +-
 ld/testsuite/ld-elf/elf.exp                |  2 +-
 ld/testsuite/ld-elf/shared.exp             |  4 +-
 libiberty/configure                        |  4 +-

1 files changed, 21 insertions, 23 deletions

diff --git a/ld/configure.tgt b/ld/configure.tgt
index 6c53539..075febf 100644
--- a/ld/configure.tgt
+++ b/ld/configure.tgt
@@ -135,10 +135,10 @@ arm*-*-freebsd* | arm-*-kfreebsd*-gnu)
 			targ_emul=armelf_fbsd
 			targ_extra_emuls="armelfb_fbsd armelf"
 			;;
-armeb-*-netbsdelf*)	targ_emul=armelfb_nbsd;
+armeb-*-netbsd*)	targ_emul=armelfb_nbsd;
 			targ_extra_emuls="armelf_nbsd armelf"
 			;;
-arm-*-netbsdelf*)	targ_emul=armelf_nbsd;
+arm-*-netbsd*)	targ_emul=armelf_nbsd;
 			targ_extra_emuls="armelfb_nbsd armelf"
 			;;
 arm-*-nto*)		targ_emul=armnto
@@ -340,7 +340,10 @@ i[3-7]86-*-solaris*)	targ_emul=elf_i386_ldso
 			targ_extra_emuls="elf_i386"
 			targ_extra_libpath=$targ_extra_emuls
 			;;
-i[3-7]86-*-netbsdelf* | \
+i[3-7]86-*-netbsdpe*)	targ_emul=i386pe
+			targ_extra_ofiles="deffilep.o pe-dll.o"
+			;;
+i[3-7]86-*-netbsd* | \
 i[3-7]86-*-netbsd*-gnu* | \
 i[3-7]86-*-knetbsd*-gnu | \
 i[3-7]86-*-openbsd*)
@@ -443,7 +446,7 @@ m68hc11-*-*|m6811-*-*)	targ_emul=m68hc11elf
 m68hc12-*-*|m6812-*-*)	targ_emul=m68hc12elf
 			targ_extra_emuls="m68hc12elfb m68hc11elf m68hc11elfb"
 			;;
-m68*-*-netbsdelf*)	targ_emul=m68kelfnbsd
+m68*-*-netbsd*)	targ_emul=m68kelfnbsd
 			;;
 m68*-*-*)		targ_emul=m68kelf
 			;;
@@ -809,10 +812,16 @@ sh*eb-*-linux*)		targ_emul=shelf_linux
 sh*-*-linux*)		targ_emul=shlelf_linux
 			targ_extra_emuls="shlelf_fd"
 			;;
-sh*l*-*-netbsdelf*)	targ_emul=shlelf_nbsd
+sh*l*-*-netbsdaout*)	targ_emul=shl
+			targ_extra_emuls=sh
+			;;
+sh*-*-netbsdaout*)	targ_emul=sh
+			targ_extra_emuls=shl
+			;;
+sh*l*-*-netbsd*)	targ_emul=shlelf_nbsd
 			targ_extra_emuls=shelf_nbsd
 			;;
-sh*-*-netbsdelf*)	targ_emul=shelf_nbsd
+sh*-*-netbsd*)	targ_emul=shelf_nbsd
 			targ_extra_emuls=shlelf_nbsd
 			;;
 shle*-*-elf* | sh[1234]*le*-*-elf | shle*-*-kaos*)
@@ -913,13 +922,12 @@ tilepro-*-*)		targ_emul=elf32tilepro
 v850*-*-*)		targ_emul=v850_rh850
 			targ_extra_emuls=v850
 			;;
-vax-*-netbsdelf*)	targ_emul=elf32vax
-			targ_extra_emuls=vaxnbsd
-			;;
-vax-*-netbsdaout* | vax-*-netbsd*)
-			targ_emul=vaxnbsd
+vax-*-netbsdaout*)	targ_emul=vaxnbsd
 			targ_extra_emuls=elf32vax
 			;;
+vax-*-netbsd*)		targ_emul=elf32vax
+			targ_extra_emuls=vaxnbsd
+			;;
 vax-*-linux-*)		targ_emul=elf32vax
 			;;
 visium-*-elf)		targ_emul=elf32visium
@@ -951,19 +959,9 @@ x86_64-*-netbsd* | x86_64-*-openbsd*)
 			targ_emul=elf_x86_64
 			targ_extra_emuls="elf_i386 elf_iamcu elf_l1om elf_k1om"
 			tdir_elf_iamcu=`echo ${targ_alias} | \
-			    sed -e 's/x86_64/i386/'`
-			case "${tdir_elf_iamcu}" in
-			*-netbsdelf*)   ;;
-			*)		tdir_elf_iamcu=`echo ${tdir_elf_iamcu} | \
-					sed -e 's/netbsd/netbsdelf/'`;;
-			esac
+			    sed -e 's/x86_64/i386/' -e 's/aout//'`
 			tdir_elf_i386=`echo ${targ_alias} | \
-			    sed -e 's/x86_64/i386/'`
-			case "${tdir_elf_i386}" in
-			*-netbsdelf*)   ;;
-			*)		tdir_elf_i386=`echo ${tdir_elf_i386} | \
-					sed -e 's/netbsd/netbsdelf/'`;;
-			esac
+			    sed -e 's/x86_64/i386/' -e 's/aout//'`
 			;;
 x86_64-*-elf* | x86_64-*-rtems* | x86_64-*-fuchsia* | x86_64-*-genode*)
 			targ_emul=elf_x86_64