Fix all our unused parameter warnings so we let GCC report them.

There were a couple of genuine bugs here (fixed), plus there's a missing
feature in trace.cc that I've just added a TODO for.

Also note that I haven't touched the compilers; this warning is still
explicitly disabled for that code. I'll do that when there's less going
on in those directories.

Change-Id: Ic3570bf82411a07c7530bfaf1995ac995b9fc00f
diff --git a/src/java_lang_Thread.cc b/src/java_lang_Thread.cc
index 0871bdd..52c5378 100644
--- a/src/java_lang_Thread.cc
+++ b/src/java_lang_Thread.cc
@@ -30,7 +30,7 @@
   return AddLocalReference<jobject>(env, Thread::Current()->GetPeer());
 }
 
-static jboolean Thread_interrupted(JNIEnv* env, jclass) {
+static jboolean Thread_interrupted(JNIEnv*, jclass) {
   return Thread::Current()->Interrupted();
 }