gdb, gdbserver, python, testsuite: Remove MPX.

GDB deprecated the commands "show/set mpx bound" in GDB 15.1, as Intel
listed Intel(R) Memory Protection Extensions (MPX) as removed in 2019.
MPX is also deprecated in gcc (since v9.1), the linux kernel (since v5.6)
and glibc (since v2.35).  Let's now remove MPX support in GDB completely.

This includes the removal of:
- MPX functionality including register support
- deprecated mpx commands
- i386 and amd64 implementation of the hooks report_signal_info and
  get_siginfo_type
- tests
- and pretty printer.

We keep MPX register numbers to not break compatibility with old gdbservers.

Approved-By: Felix Willgerodt <felix.willgerodt@intel.com>

gdb/python/lib/gdb/printer/bound_registers.py

@@ -1,39 +0,0 @@
-# Pretty-printers for bounds registers.
-# Copyright (C) 2013-2024 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/>.
-
-import gdb
-import gdb.printing
-
-
-class MpxBound128Printer(gdb.ValuePrinter):
-    """Adds size field to a mpx __gdb_builtin_type_bound128 type."""
-
-    def __init__(self, val):
-        self.__val = val
-
-    def to_string(self):
-        upper = self.__val["ubound"]
-        lower = self.__val["lbound"]
-        size = upper - lower
-        if size > -1:
-            size = size + 1
-        result = "{lbound = %s, ubound = %s} : size %s" % (lower, upper, size)
-        return result
-
-
-gdb.printing.add_builtin_pretty_printer(
-    "mpx_bound128", "^builtin_type_bound128", MpxBound128Printer
-)