Warn if a thread attaches without a name and blow up if a thread detaches while running.

Also don't crash if a thread attaches without a name. Doing so is allowed, even
if it's not a good idea.

Change-Id: If5796af689e9221ce21f443023b0d793a8be15b0
diff --git a/src/utils.h b/src/utils.h
index 9c18093..b49d764 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -283,7 +283,7 @@
 
 // Sets the name of the current thread. The name may be truncated to an
 // implementation-defined limit.
-void SetThreadName(const char* name);
+void SetThreadName(const char* thread_name);
 
 // Find $ANDROID_ROOT, /system, or abort
 const char* GetAndroidRoot();