perf_counter tools: add in basic glue from Git

First very raw version at having a central 'perf' command and
a list of subcommands:

  perf top
  perf stat
  perf record
  perf report
  ...

This is done by picking up Git's collection of utility functions,
and hacking them to build fine in this new environment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/perf_counter/help.h b/Documentation/perf_counter/help.h
new file mode 100644
index 0000000..56bc154
--- /dev/null
+++ b/Documentation/perf_counter/help.h
@@ -0,0 +1,29 @@
+#ifndef HELP_H
+#define HELP_H
+
+struct cmdnames {
+	int alloc;
+	int cnt;
+	struct cmdname {
+		size_t len; /* also used for similarity index in help.c */
+		char name[FLEX_ARRAY];
+	} **names;
+};
+
+static inline void mput_char(char c, unsigned int num)
+{
+	while(num--)
+		putchar(c);
+}
+
+void load_command_list(const char *prefix,
+		struct cmdnames *main_cmds,
+		struct cmdnames *other_cmds);
+void add_cmdname(struct cmdnames *cmds, const char *name, int len);
+/* Here we require that excludes is a sorted list. */
+void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes);
+int is_in_cmdlist(struct cmdnames *c, const char *s);
+void list_commands(const char *title, struct cmdnames *main_cmds,
+		   struct cmdnames *other_cmds);
+
+#endif /* HELP_H */