Add variable support in appmap

Signed-off-by: xcgspring <xcg1987xcg@126.com>
Fix issue

Signed-off-by: xcgspring <xcg1987xcg@126.com>
fix issues

Signed-off-by: xcgspring <xcg1987xcg@126.com>
Fix issue

Signed-off-by: xcgspring <xcg1987xcg@126.com>