perf probe: Walk function lines in lexical blocks

Since some inlined functions are in lexical blocks of given function, we
have to recursively walk through the DIE tree.  Without this fix,
perf-probe -L can miss the inlined functions which is in a lexical block
(like if (..) { func() } case.)

However, even though, to walk the lines in a given function, we don't
need to follow the children DIE of inlined functions because those do
not have any lines in the specified function.

We need to walk though whole trees only if we walk all lines in a given
file, because an inlined function can include another inlined function
in the same file.

Fixes: b0e9cb28 ("perf probe: Fix to search nested inlined functions in CU")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157190836514.1859.15996864849678136353.stgit@devnote2


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