gdb: Consolidate 32bit-pkeys.xml and 64bit-pkeys.xml

1. Since 32bit-pkeys.xml and 64bit-pkeys.xml are identical, consolidate
them into a single keys.xml.
2. Enable PKU for x32 to fix:

$ gdbserver :123456 x32-program
...
.../gdbserver/regcache.cc:255: A problem internal to GDBserver has been detected
.
Unknown register pkru requested

on Tiger Lake.

5 files changed, 3 insertions, 31 deletions

diff --git a/gdb/features/Makefile b/gdb/features/Makefile
index 68e17d0..a2bb2a5 100644
--- a/gdb/features/Makefile
+++ b/gdb/features/Makefile
@@ -216,7 +216,6 @@ FEATURE_XMLFILES = aarch64-core.xml \
 	i386/32bit-avx.xml \
 	i386/32bit-mpx.xml \
 	i386/32bit-avx512.xml \
-	i386/32bit-pkeys.xml \
 	i386/32bit-segments.xml \
 	i386/64bit-avx512.xml \
 	i386/64bit-core.xml \
@@ -224,8 +223,8 @@ FEATURE_XMLFILES = aarch64-core.xml \
 	i386/64bit-segments.xml \
 	i386/64bit-avx.xml \
 	i386/64bit-linux.xml \
-	i386/64bit-pkeys.xml \
 	i386/64bit-sse.xml \
+	i386/pkeys.xml \
 	i386/x32-core.xml \
 	loongarch/base32.xml \
 	loongarch/base64.xml \
diff --git a/gdb/features/i386/64bit-pkeys.c b/gdb/features/i386/64bit-pkeys.c
deleted file mode 100644
index 83001d4..0000000
--- a/gdb/features/i386/64bit-pkeys.c
+++ /dev/null
@@ -1,14 +0,0 @@
-/* THIS FILE IS GENERATED.  -*- buffer-read-only: t -*- vi:set ro:
-  Original: 64bit-pkeys.xml */
-
-#include "gdbsupport/tdesc.h"
-
-static int
-create_feature_i386_64bit_pkeys (struct target_desc *result, long regnum)
-{
-  struct tdesc_feature *feature;
-
-  feature = tdesc_create_feature (result, "org.gnu.gdb.i386.pkeys");
-  tdesc_create_reg (feature, "pkru", regnum++, 1, NULL, 32, "uint32");
-  return regnum;
-}
diff --git a/gdb/features/i386/64bit-pkeys.xml b/gdb/features/i386/64bit-pkeys.xml
deleted file mode 100644
index db6c10a..0000000
--- a/gdb/features/i386/64bit-pkeys.xml
+++ /dev/null
@@ -1,13 +0,0 @@
-<?xml version="1.0"?>
-<!-- Copyright (C) 2016-2022 Free Software Foundation, Inc.
-
-     Copying and distribution of this file, with or without modification,
-     are permitted in any medium without royalty provided the copyright
-     notice and this notice are preserved.  -->
-
-<!DOCTYPE feature SYSTEM "gdb-target.dtd">
-<feature name="org.gnu.gdb.i386.pkeys">
-
-  <reg name="pkru" bitsize="32" type="uint32"/>
-
-</feature>
diff --git a/gdb/features/i386/32bit-pkeys.c b/gdb/features/i386/pkeys.c
index 5e9087e..955d563 100644
--- a/gdb/features/i386/32bit-pkeys.c
+++ b/gdb/features/i386/pkeys.c
@@ -1,10 +1,10 @@
 /* THIS FILE IS GENERATED.  -*- buffer-read-only: t -*- vi:set ro:
-  Original: 32bit-pkeys.xml */
+  Original: pkeys.xml */
 
 #include "gdbsupport/tdesc.h"
 
 static int
-create_feature_i386_32bit_pkeys (struct target_desc *result, long regnum)
+create_feature_i386_pkeys (struct target_desc *result, long regnum)
 {
   struct tdesc_feature *feature;
 
diff --git a/gdb/features/i386/32bit-pkeys.xml b/gdb/features/i386/pkeys.xml
index db6c10a..db6c10a 100644
--- a/gdb/features/i386/32bit-pkeys.xml
+++ b/gdb/features/i386/pkeys.xml