Show function name based on dladdr

If there's no dwarf and symbol table, this will be a last resort.
(mainly on macOS)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65897 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

addr2line.c

@@ -2170,6 +2170,8 @@ rb_dump_backtrace_with_lines(int num_traces, void **traces)
 	    path = info.dli_fname;
 	    obj->path = path;
 	    lines[i].path = path;
+            lines[i].sname = info.dli_sname;
+            lines[i].saddr = (uintptr_t)info.dli_saddr;
 	    strlcpy(binary_filename, path, PATH_MAX);
 	    if (fill_lines(num_traces, traces, 1, &obj, lines, i) == (uintptr_t)-1)
 		break;