gdb/testsuite: use the correct .debug_str section name for DW_FORM_strp

When handling DWARF attributes of the form DW_FORM_strp the strings
should be placed in the .debug_str section, not .debug_string as they
currently are by the DWARF assembler (in lib/dwarf.exp).

I've added a test.  This is as much to test the DWARF generator as it
is to test GDB as GCC makes frequent use of DW_FORM_strp so we can be
pretty sure this part of GDB is already well tested.

gdb/testsuite/ChangeLog:

	* gdb.dwarf2/dw2-using-debug-str.c: New file.
	* gdb.dwarf2/dw2-using-debug-str.exp: New file.
	* lib/dwarf.exp (Dwarf::DW_FORM_strp): Create .debug_str section,
	not .debug_string.

1 files changed, 28 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.dwarf2/dw2-using-debug-str.c b/gdb/testsuite/gdb.dwarf2/dw2-using-debug-str.c
new file mode 100644
index 0000000..27f7f0d
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-using-debug-str.c
@@ -0,0 +1,28 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2021 Free Software Foundation, Inc.
+
+   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.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Our fake object.  */
+int global_var[100];
+
+int
+main (int argc, char **argv)
+{
+  asm ("main_label: .globl main_label");
+
+  return 0;
+}