Add the missing link between compiled code and the debugger.

When a debugger connects and disconnects, we now let compiled code know that we
need to be kept informed about what's going on.

Also fix a threading bug when threads exit with a debugger attached.

Also some minor tidying, mostly involving naming.

Change-Id: Iba0e8b9d192ac76ba1cd29a8b1e6d94f6f20dea8
diff --git a/src/runtime_support.h b/src/runtime_support.h
index 00ca5bd..0b9e0c4 100644
--- a/src/runtime_support.h
+++ b/src/runtime_support.h
@@ -51,10 +51,11 @@
 extern int64_t F2L(float f);
 
 }  // namespace art
-/* Helper for both JNI and regular compiled code */
-extern "C" void art_deliver_exception_from_code(void*);
 
+// Helpers for both compiled code and libart.
+extern "C" void art_deliver_exception_from_code(void*);
 extern "C" void art_proxy_invoke_handler();
+extern "C" void art_update_debugger(void*, void*, int32_t, void*);
 
 #if defined(__arm__)
   /* Compiler helpers */
@@ -102,7 +103,6 @@
   extern "C" void art_trace_entry_from_code(void*);
   extern "C" void art_trace_exit_from_code();
   extern "C" void* art_resolve_string_from_code(void*, uint32_t);
-  extern "C" void art_update_debugger(void*, void*, int32_t, void*);
   extern "C" void art_work_around_app_jni_bugs();
 
   /* Conversions */