process_info: add get process count api

Author: bradjc

libtock/kernel/process_info.c

@@ -6,6 +6,10 @@ bool libtock_process_info_exists(void) {
   return libtock_process_info_driver_exists();
 }
 
+returncode_t libtock_process_info_get_process_count(uint32_t* count) {
+  return libtock_process_info_command_get_process_count(count);
+}
+
 returncode_t libtock_process_info_get_process_ids(uint8_t* buffer, size_t buffer_length, uint32_t* count) {
   returncode_t ret;
 

libtock/kernel/process_info.h

@@ -9,6 +9,9 @@ extern "C" {
 // Check if the driver exists.
 bool libtock_process_info_exists(void);
 
+// Get the number of running processes on the board.
+returncode_t libtock_process_info_get_process_count(uint32_t* count);
+
 // Get an array of `uint32_t` process IDs.
 //
 // `count` is set to the number of process IDs.