perf tools: Recognize hugetlb mapping as anon mapping

Hugetlbfs mapping should be recognized as anon mapping so user has a
chance to create /tmp/perf-<pid>.map file for symbol resolving. This
patch utilizes MAP_HUGETLB to identify hugetlb mapping.

After this patch, if perf is started before a program starts using huge
pages (so perf gets MMAP2 events from kernel), perf is able to recognize
hugetlb mapping as anon mapping.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1473137909-142064-2-git-send-email-wangnan0@huawei.com


Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>