perf tools: Fixup get_current_dir_name() compilation

strdup() prototype doesn't live in stdlib.h .

Add limits.h for PATH_MAX definition as well.

This fixes the build on Android.

Signed-off-by: Alexey Dobriyan (SK hynix) <adobriyan@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/YRukaQbrgDWhiwGr@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Remove duplicate headers

Removed headers which are included twice.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1566663319-4283-1-git-send-email-jrdr.linux@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Move get_current_dir_name() cond prototype out of util.h

And in a separate header, so that we erode util.h a bit more.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-xpzvuu9d0gei9jl9bkzgobln@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools build feature: Check if get_current_dir_name() is available

As the namespace support code will use this, which is not available in
some non _GNU_SOURCE libraries such as Android's bionic used in my
container build tests (r12b and r15c at the moment).

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-x56ypm940pwclwu45d7jfj47@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>