scripts/gdb/symbols: add specific ko module load command

Patch series "Add GDB memory helper commands", v2.

I've created some GDB commands I think useful when I debug some memory
issues and kernel module issue.

For memory issue, we would like to get slabinfo, slabtrace, page_owner and
vmallocinfo to debug the memory issues.

For module issue, we would like to query kernel module name when we get a
module text address and load module symbol by specific path.

Patch 1-2:
 - Add kernel module related command.
Patch 3-5:
 - Prepares for the memory-related command.
Patch 6-8:
 - Add memory-related commands.


This patch (of 8):

Add lx-symbols <ko_path> command to support add specific
ko module.

Example output like below:
(gdb) lx-symbols mm/kasan/kasan_test.ko
loading @0xffff800002d30000: mm/kasan/kasan_test.ko

Link: https://lkml.kernel.org/r/20230808083020.22254-1-Kuan-Ying.Lee@mediatek.com
Link: https://lkml.kernel.org/r/20230808083020.22254-2-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>