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, 53 insertions, 53 deletions

diff --git a/opcodes/po/opcodes.pot b/opcodes/po/opcodes.pot
index e69efd7..50a01b3 100644
--- a/opcodes/po/opcodes.pot
+++ b/opcodes/po/opcodes.pot
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: bug-binutils@gnu.org\n"
-"POT-Creation-Date: 2021-07-03 15:03+0100\n"
+"POT-Creation-Date: 2021-08-11 10:45+0100\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -26,7 +26,7 @@ msgid "specified register cannot be written to"
 msgstr ""
 
 #. Invalid option.
-#: aarch64-dis.c:94 arc-dis.c:802 arm-dis.c:11652
+#: aarch64-dis.c:94 arc-dis.c:802 arm-dis.c:11669
 #, c-format
 msgid "unrecognised disassembler option: %s"
 msgstr ""
@@ -591,67 +591,67 @@ msgstr ""
 msgid "invalid position, should be one of: 0,4,8,...124."
 msgstr ""
 
-#: arm-dis.c:5187
+#: arm-dis.c:5204
 msgid "Select raw register names"
 msgstr ""
 
-#: arm-dis.c:5189
+#: arm-dis.c:5206
 msgid "Select register names used by GCC"
 msgstr ""
 
-#: arm-dis.c:5191
+#: arm-dis.c:5208
 msgid "Select register names used in ARM's ISA documentation"
 msgstr ""
 
-#: arm-dis.c:5193
+#: arm-dis.c:5210
 msgid "Assume all insns are Thumb insns"
 msgstr ""
 
-#: arm-dis.c:5194
+#: arm-dis.c:5211
 msgid "Examine preceding label to determine an insn's type"
 msgstr ""
 
-#: arm-dis.c:5195
+#: arm-dis.c:5212
 msgid "Select register names used in the APCS"
 msgstr ""
 
-#: arm-dis.c:5197
+#: arm-dis.c:5214
 msgid "Select register names used in the ATPCS"
 msgstr ""
 
-#: arm-dis.c:5199
+#: arm-dis.c:5216
 msgid "Select special register names used in the ATPCS"
 msgstr ""
 
-#: arm-dis.c:5201
+#: arm-dis.c:5218
 msgid "Enable CDE extensions for coprocessor N space"
 msgstr ""
 
-#: arm-dis.c:8373
+#: arm-dis.c:8390
 msgid "<illegal precision>"
 msgstr ""
 
-#: arm-dis.c:11613
+#: arm-dis.c:11630
 #, c-format
 msgid "unrecognised register name set: %s"
 msgstr ""
 
-#: arm-dis.c:11627
+#: arm-dis.c:11644
 #, c-format
 msgid "cde coprocessor not between 0-7: %s"
 msgstr ""
 
-#: arm-dis.c:11633
+#: arm-dis.c:11650
 #, c-format
 msgid "coproc must have an argument: %s"
 msgstr ""
 
-#: arm-dis.c:11646
+#: arm-dis.c:11663
 #, c-format
 msgid "coprocN argument takes options \"generic\", \"cde\", or \"CDE\": %s"
 msgstr ""
 
-#: arm-dis.c:12357
+#: arm-dis.c:12374
 #, c-format
 msgid ""
 "\n"
@@ -1055,11 +1055,11 @@ msgstr ""
 msgid "Don't understand 0x%x \n"
 msgstr ""
 
-#: i386-dis.c:8591
+#: i386-dis.c:8642
 msgid "<internal disassembler error>"
 msgstr ""
 
-#: i386-dis.c:8900
+#: i386-dis.c:8952
 #, c-format
 msgid ""
 "\n"
@@ -1068,175 +1068,175 @@ msgid ""
 "with the -M switch (multiple options should be separated by commas):\n"
 msgstr ""
 
-#: i386-dis.c:8904
+#: i386-dis.c:8956
 #, c-format
 msgid "  x86-64      Disassemble in 64bit mode\n"
 msgstr ""
 
-#: i386-dis.c:8905
+#: i386-dis.c:8957
 #, c-format
 msgid "  i386        Disassemble in 32bit mode\n"
 msgstr ""
 
-#: i386-dis.c:8906
+#: i386-dis.c:8958
 #, c-format
 msgid "  i8086       Disassemble in 16bit mode\n"
 msgstr ""
 
-#: i386-dis.c:8907
+#: i386-dis.c:8959
 #, c-format
 msgid "  att         Display instruction in AT&T syntax\n"
 msgstr ""
 
-#: i386-dis.c:8908
+#: i386-dis.c:8960
 #, c-format
 msgid "  intel       Display instruction in Intel syntax\n"
 msgstr ""
 
-#: i386-dis.c:8909
+#: i386-dis.c:8961
 #, c-format
 msgid ""
 "  att-mnemonic\n"
 "              Display instruction in AT&T mnemonic\n"
 msgstr ""
 
-#: i386-dis.c:8911
+#: i386-dis.c:8963
 #, c-format
 msgid ""
 "  intel-mnemonic\n"
 "              Display instruction in Intel mnemonic\n"
 msgstr ""
 
-#: i386-dis.c:8913
+#: i386-dis.c:8965
 #, c-format
 msgid "  addr64      Assume 64bit address size\n"
 msgstr ""
 
-#: i386-dis.c:8914
+#: i386-dis.c:8966
 #, c-format
 msgid "  addr32      Assume 32bit address size\n"
 msgstr ""
 
-#: i386-dis.c:8915
+#: i386-dis.c:8967
 #, c-format
 msgid "  addr16      Assume 16bit address size\n"
 msgstr ""
 
-#: i386-dis.c:8916
+#: i386-dis.c:8968
 #, c-format
 msgid "  data32      Assume 32bit data size\n"
 msgstr ""
 
-#: i386-dis.c:8917
+#: i386-dis.c:8969
 #, c-format
 msgid "  data16      Assume 16bit data size\n"
 msgstr ""
 
-#: i386-dis.c:8918
+#: i386-dis.c:8970
 #, c-format
 msgid "  suffix      Always display instruction suffix in AT&T syntax\n"
 msgstr ""
 
-#: i386-dis.c:8919
+#: i386-dis.c:8971
 #, c-format
 msgid "  amd64       Display instruction in AMD64 ISA\n"
 msgstr ""
 
-#: i386-dis.c:8920
+#: i386-dis.c:8972
 #, c-format
 msgid "  intel64     Display instruction in Intel64 ISA\n"
 msgstr ""
 
-#: i386-dis.c:9484
+#: i386-dis.c:9541
 msgid "64-bit address is disabled"
 msgstr ""
 
-#: i386-gen.c:851
+#: i386-gen.c:857
 #, c-format
 msgid "%s: error: "
 msgstr ""
 
-#: i386-gen.c:1007
+#: i386-gen.c:1013
 #, c-format
 msgid "%s: %d: unknown bitfield: %s\n"
 msgstr ""
 
-#: i386-gen.c:1009
+#: i386-gen.c:1015
 #, c-format
 msgid "unknown bitfield: %s\n"
 msgstr ""
 
-#: i386-gen.c:1072
+#: i386-gen.c:1078
 #, c-format
 msgid "%s: %d: missing `)' in bitfield: %s\n"
 msgstr ""
 
-#: i386-gen.c:1173
+#: i386-gen.c:1179
 #, c-format
 msgid "unknown broadcast operand: %s\n"
 msgstr ""
 
-#: i386-gen.c:1228
+#: i386-gen.c:1234
 #, c-format
 msgid "%s:%d: Conflicting opcode space specifications\n"
 msgstr ""
 
-#: i386-gen.c:1232
+#: i386-gen.c:1238
 #, c-format
 msgid "%s:%d: Warning: redundant opcode space specification\n"
 msgstr ""
 
-#: i386-gen.c:1241
+#: i386-gen.c:1247
 #, c-format
 msgid "%s:%d: Conflicting prefix specifications\n"
 msgstr ""
 
-#: i386-gen.c:1245
+#: i386-gen.c:1251
 #, c-format
 msgid "%s:%d: Warning: redundant prefix specification\n"
 msgstr ""
 
-#: i386-gen.c:1455
+#: i386-gen.c:1461
 #, c-format
 msgid "%s:%d: %s: unrecognized opcode encoding space\n"
 msgstr ""
 
-#: i386-gen.c:1461
+#: i386-gen.c:1467
 #, c-format
 msgid "%s:%d: %s: residual opcode (0x%0*llx) too large\n"
 msgstr ""
 
-#: i386-gen.c:1883
+#: i386-gen.c:1889
 #, c-format
 msgid "can't find i386-reg.tbl for reading, errno = %s\n"
 msgstr ""
 
-#: i386-gen.c:1961
+#: i386-gen.c:1967
 #, c-format
 msgid "can't create i386-init.h, errno = %s\n"
 msgstr ""
 
-#: i386-gen.c:2051 ia64-gen.c:2829
+#: i386-gen.c:2057 ia64-gen.c:2829
 #, c-format
 msgid "unable to change directory to \"%s\", errno = %s\n"
 msgstr ""
 
-#: i386-gen.c:2065 i386-gen.c:2070
+#: i386-gen.c:2071 i386-gen.c:2076
 #, c-format
 msgid "CpuMax != %d!\n"
 msgstr ""
 
-#: i386-gen.c:2074
+#: i386-gen.c:2080
 #, c-format
 msgid "%d unused bits in i386_cpu_flags.\n"
 msgstr ""
 
-#: i386-gen.c:2089
+#: i386-gen.c:2095
 #, c-format
 msgid "%d unused bits in i386_operand_type.\n"
 msgstr ""
 
-#: i386-gen.c:2103
+#: i386-gen.c:2109
 #, c-format
 msgid "can't create i386-tbl.h, errno = %s\n"
 msgstr ""