LD/testsuite: Add tests for archive handling

Add basic verification for archives to work, regular and thin, in the
link.  Refer to PR binutils/33484 and PR binutils/33485 for targets that
fail these basic checks, where `ar' fails to add subsequent members to
the archive or fails to add symbols from subsequent members to the map
respectively, for thin archives.

NB symbol names chosen such as to avoid a clash with Z80 CPU registers.

ld/testsuite/ld-archive/a.s

@@ -0,0 +1,4 @@
+	.data
+	.globl	aa
+aa:
+	.dc.a	bb

ld/testsuite/ld-archive/abc.nd

@@ -0,0 +1,7 @@
+#...
+[0-9a-f]+ D aa
+#...
+[0-9a-f]+ D bb
+#...
+[0-9a-f]+ D cc
+#pass

ld/testsuite/ld-archive/abc.s

@@ -0,0 +1,7 @@
+	.text
+	.globl	ff
+ff:
+	.data
+	.globl	cc
+cc:
+	.dc.a	aa, bb

ld/testsuite/ld-archive/abcde.nd

@@ -0,0 +1,11 @@
+#...
+[0-9a-f]+ D aa
+#...
+[0-9a-f]+ D bb
+#...
+[0-9a-f]+ D cc
+#...
+[0-9a-f]+ D dd
+#...
+[0-9a-f]+ D ee
+#pass

ld/testsuite/ld-archive/abcde.s

@@ -0,0 +1,7 @@
+	.text
+	.globl	ff
+ff:
+	.data
+	.globl	ee
+ee:
+	.dc.a	aa, cc

ld/testsuite/ld-archive/archive.exp

@@ -0,0 +1,100 @@
+# Test for archive handling.
+# Copyright (C) 2025 Free Software Foundation, Inc.
+#
+# This file is part of the GNU Binutils.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; see the file COPYING3. If not,
+# see <http://www.gnu.org/licenses/>.
+#
+
+remote_file host delete \
+    "tmpdir/ab.a" "tmpdir/cd.a" "tmpdir/abt.a" "tmpdir/cdt.a"
+
+run_ld_link_tests {
+    {"First regular archive create"     ""   "" "" {a.s b.s} {} "ab.a"  }
+    {"Second regular archive create"    ""   "" "" {c.s d.s} {} "cd.a"  }
+    {"First thin archive create"        "T"  "" "" {a.s b.s} {} "abt.a" }
+    {"Second thin archive create"       "T"  "" "" {c.s d.s} {} "cdt.a" }
+}
+
+set old_ldflags $LDFLAGS
+
+# Prevent our otherwise unused data symbols from being GC'd on XCOFF targets.
+if { [is_xcoff_format] } {
+    append LDFLAGS " -bexpall"
+}
+
+# For MS-DOS there's no way to keep symbols, so just check for success.
+run_ld_link_tests [list \
+    [list "Regular archive link" \
+	"-e ff" "tmpdir/ab.a" \
+	"" {abc.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abc.nd}} }] \
+	"abc" \
+    ] \
+]
+setup_xfail "binutils/33484" "alpha*-*-linux*ecoff*" "alpha*-*-osf*"
+setup_xfail "binutils/33485" "cris-*-*aout*" "i\[3-7\]86-*-bsd*" \
+    "i\[3-7\]86-*-msdos*" "pdp11-*-*"
+run_ld_link_tests [list \
+    [list "Thin archive link" \
+	"-e ff" "tmpdir/abt.a" \
+	"" {abc.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abc.nd}} }] \
+	"abtc" \
+    ] \
+]
+run_ld_link_tests [list \
+    [list "Regular archive plus regular link" \
+	"-e ff" "tmpdir/ab.a tmpdir/cd.a" \
+	"" {abcde.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abcde.nd}} }] \
+	"abcde" \
+    ] \
+]
+setup_xfail "binutils/33484" "alpha*-*-linux*ecoff*" "alpha*-*-osf*"
+setup_xfail "binutils/33485" "cris-*-*aout*" "i\[3-7\]86-*-bsd*" \
+    "i\[3-7\]86-*-msdos*" "pdp11-*-*"
+run_ld_link_tests [list \
+    [list "Regular archive plus thin link" \
+	"-e ff" "tmpdir/ab.a tmpdir/cdt.a" \
+	"" {abcde.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abcde.nd}} }] \
+	"abcdte" \
+    ] \
+]
+setup_xfail "binutils/33484" "alpha*-*-linux*ecoff*" "alpha*-*-osf*"
+setup_xfail "binutils/33485" "cris-*-*aout*" "i\[3-7\]86-*-bsd*" \
+    "i\[3-7\]86-*-msdos*" "pdp11-*-*"
+run_ld_link_tests [list \
+    [list "Thin archive plus regular link" \
+	"-e ff" "tmpdir/abt.a tmpdir/cd.a" \
+	"" {abcde.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abcde.nd}} }] \
+	"abtcde" \
+    ] \
+]
+setup_xfail "binutils/33484" "alpha*-*-linux*ecoff*" "alpha*-*-osf*"
+setup_xfail "binutils/33485" "cris-*-*aout*" "i\[3-7\]86-*-bsd*" \
+    "i\[3-7\]86-*-msdos*" "pdp11-*-*"
+run_ld_link_tests [list \
+    [list "Thin archive plus thin link" \
+	"-e ff" "tmpdir/abt.a tmpdir/cdt.a" \
+	"" {abcde.s} \
+	[expr { [istarget "*-*-msdos"] ? {} : {{nm "" abcde.nd}} }] \
+	"abtcdte" \
+    ] \
+]
+
+set LDFLAGS $old_ldflags

ld/testsuite/ld-archive/b.s

@@ -0,0 +1,4 @@
+	.data
+	.globl	bb
+bb:
+	.dc.a	aa

ld/testsuite/ld-archive/c.s

@@ -0,0 +1,4 @@
+	.data
+	.globl	cc
+cc:
+	.dc.a	dd

ld/testsuite/ld-archive/d.s

@@ -0,0 +1,4 @@
+	.data
+	.globl	dd
+dd:
+	.dc.a	cc