[pushed] Fix aarch64-linux-hw-point.c build problem

[Kevin Buettner via Gdb-patches <gdb-patches@sourceware.org>]

Due to a recent glibc header file change, the file
nat/aarch64-linux-hw-point.c no longer builds on Fedora rawhide.

An enum for PTRACE_SYSEMU is now provided by <sys/ptrace.h>.  In the
past, PTRACE_SYSEMU was defined only in <asm/ptrace.h>.  This is
what it looks like...

In <asm/ptrace.h>:

 #define PTRACE_SYSEMU		  31

In <sys/ptrace.h>:

enum __ptrace_request
{
  ...
  PTRACE_SYSEMU = 31,
 #define PT_SYSEMU PTRACE_SYSEMU

  ...
}

When <asm/ptrace.h> and <sys/ptrace.h> are both included in a source
file, we run into the following build problem when the former is
included before the latter:

In file included from nat/aarch64-linux-hw-point.c:26:
/usr/include/sys/ptrace.h:86:3: error: expected identifier before numeric constant
   86 |   PTRACE_SYSEMU = 31,
      |   ^~~~~~~~~~~~~

(There are more errors after this one too.)

The file builds without error when <asm/ptrace.h> is included after
<sys/ptrace.h>.  I found that this is already done in
nat/aarch64-sve-linux-ptrace.h (which is included by
nat/aarch64-linux-ptrace.c).

I've tested this change on Fedora rawhide and Fedora 33, both
running on an aarch64 machine.

gdb/ChangeLog:

	* nat/aarch64-linux-hw-point.c: Include <asm/ptrace.h> after
	<sys/ptrace.h>.
---
 gdb/ChangeLog                    | 5 +++++
 gdb/nat/aarch64-linux-hw-point.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 00a71fe9025..f7052421935 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2021-02-24  Kevin Buettner  <kevinb@redhat.com>
+
+	* nat/aarch64-linux-hw-point.c: Include <asm/ptrace.h> after
+	<sys/ptrace.h>.
+
 2021-02-24  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* exec.c (set_section_command): Move variable declarations into
diff --git a/gdb/nat/aarch64-linux-hw-point.c b/gdb/nat/aarch64-linux-hw-point.c
index 73e4edd68cb..0278ac2bb28 100644
--- a/gdb/nat/aarch64-linux-hw-point.c
+++ b/gdb/nat/aarch64-linux-hw-point.c
@@ -23,8 +23,8 @@
 #include "aarch64-linux-hw-point.h"
 
 #include <sys/uio.h>
-#include <asm/ptrace.h>
 #include <sys/ptrace.h>
+#include <asm/ptrace.h>
 #include <elf.h>
 
 /* Number of hardware breakpoints/watchpoints the target supports.
-- 
2.29.2