gdbserver: rename source files to .cc

For the same reasons outlined in the previous patch, this patch renames
gdbserver source files to .cc.

I have moved the "-x c++" switch to only those rules that require it.

gdbserver/ChangeLog:

	* Makefile.in: Rename source files from .c to .cc.
	* %.c: Rename to %.cc.
	* configure.ac: Rename server.c to server.cc.
	* configure: Re-generate.

gdbserver/linux-arm-tdesc.cc

@@ -0,0 +1,65 @@
+/* Copyright (C) 2019-2020 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#include "server.h"
+
+#include "linux-arm-tdesc.h"
+
+#include "tdesc.h"
+#include "arch/arm.h"
+#include <inttypes.h>
+
+/* All possible Arm target descriptors.  */
+static struct target_desc *tdesc_arm_list[ARM_FP_TYPE_INVALID];
+
+/* See linux-arm-tdesc.h.  */
+
+const target_desc *
+arm_linux_read_description (arm_fp_type fp_type)
+{
+  struct target_desc *tdesc = tdesc_arm_list[fp_type];
+
+  if (tdesc == nullptr)
+    {
+      tdesc = arm_create_target_description (fp_type);
+
+      static const char *expedite_regs[] = { "r11", "sp", "pc", 0 };
+      init_target_desc (tdesc, expedite_regs);
+
+      tdesc_arm_list[fp_type] = tdesc;
+    }
+
+  return tdesc;
+}
+
+/* See linux-arm-tdesc.h.  */
+
+arm_fp_type
+arm_linux_get_tdesc_fp_type (const target_desc *tdesc)
+{
+  gdb_assert (tdesc != nullptr);
+
+  /* Many of the tdesc_arm_list entries may not have been initialised yet.  This
+     is ok, because tdesc must be one of the initialised ones.  */
+  for (int i = ARM_FP_TYPE_NONE; i < ARM_FP_TYPE_INVALID; i++)
+    {
+      if (tdesc == tdesc_arm_list[i])
+	return (arm_fp_type) i;
+    }
+
+  return ARM_FP_TYPE_INVALID;
+}