Use the event loop name instead of thread name for AOS_LOG

This kills 2 birds with 1 stone.
  1) A simulated event loop should print out the name of each event
     loop, not the program name.
  2) prctl(PR_GET_NAME, thread_name_array) can require higher privileges
     sometimes, and is un-necesary for simulations.  See 1)

Change-Id: I48731b1cabe34ec66a97f27ee720ba3081da4e94
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/aos/logging/interface.h b/aos/logging/interface.h
index f6fa249..d2663e7 100644
--- a/aos/logging/interface.h
+++ b/aos/logging/interface.h
@@ -4,6 +4,7 @@
 #include <cstdarg>
 #include <functional>
 #include <string>
+#include <string_view>
 
 #include "aos/logging/logging.h"
 #include "aos/macros.h"
@@ -29,6 +30,10 @@
 
   virtual ~LogImplementation() {}
 
+  // Returns the identifying name to be used when logging.  This could be the
+  // event loop name or the thread name.
+  virtual std::string_view MyName() = 0;
+
   // Actually logs the given message. Implementations should somehow create a
   // LogMessage and then call internal::FillInMessage.
   __attribute__((format(GOOD_PRINTF_FORMAT_TYPE, 3, 0))) virtual void DoLog(