perf symbols: Support minimal build without libelf

Now we have isolated all ELF-specific stuff, it's possible to build
without libelf. The output binary can do most of jobs but lacks (user
level) symbol information - kernel symbols are still accessable thanks
to the kallsyms.

To build perf without libelf (elfutils), give NO_LIBELF=1 to make.

For now, only 'perf probe' command is removed since it depends on
libelf/libdw heavily.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344228082-15569-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/symbol-minimal.c

@@ -0,0 +1,39 @@
+#include "symbol.h"
+
+
+int filename__read_build_id(const char *filename __used, void *bf __used,
+			    size_t size __used)
+{
+	return -1;
+}
+
+int sysfs__read_build_id(const char *filename __used, void *build_id __used,
+			 size_t size __used)
+{
+	return -1;
+}
+
+int filename__read_debuglink(const char *filename __used,
+			     char *debuglink __used, size_t size __used)
+{
+	return -1;
+}
+
+int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used,
+				struct map *map __used,
+				symbol_filter_t filter __used)
+{
+	return 0;
+}
+
+int dso__load_sym(struct dso *dso __used, struct map *map __used,
+		  const char *name __used, int fd __used,
+		  symbol_filter_t filter __used, int kmodule __used,
+		  int want_symtab __used)
+{
+	return 0;
+}
+
+void symbol__elf_init(void)
+{
+}