gdb: fix remote reply packet length.

From Ranjani in GDB 8.1, forward ported to 8.3.1

+From 90a51ab53bd761c4382f27ec1bbf8de0de215463 Mon Sep 17 00:00:00 2001
+From: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
+Date: Thu, 11 Apr 2019 20:04:46 -0700
+Subject: [PATCH] fix error with packet reply too long

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

packages/gdb/8.3.1/0006-fix-remote-debug.patch

@@ -0,0 +1,27 @@
+Index: gdb-8.3.1/gdb/remote.c
+===================================================================
+--- gdb-8.3.1.orig/gdb/remote.c
++++ gdb-8.3.1/gdb/remote.c
+@@ -8035,11 +8035,17 @@ remote_target::process_g_packet (struct
+   buf_len = strlen (rs->buf.data ());
+
+   /* Further sanity checks, with knowledge of the architecture.  */
+-  if (buf_len > 2 * rsa->sizeof_g_packet)
+-    error (_("Remote 'g' packet reply is too long (expected %ld bytes, got %d "
+-	     "bytes): %s"),
+-	   rsa->sizeof_g_packet, buf_len / 2,
+-	   rs->buf.data ());
++   if(buf_len > 2 * rsa->sizeof_g_packet) {
++        rsa->sizeof_g_packet = buf_len;
++        for(i = 0; i < gdbarch_num_regs(gdbarch); i++){
++            if(rsa->regs[i].pnum == -1)
++               continue;
++            if(rsa->regs[i].offset >= rsa->sizeof_g_packet)
++               rsa->regs[i].in_g_packet = 0;
++            else
++               rsa->regs[i].in_g_packet = 1;
++        }
++  }
+
+   /* Save the size of the packet sent to us by the target.  It is used
+      as a heuristic when determining the max size of packets that the