Remove -Wno-unused-parameter and -Wno-sign-promo from base cflags.

Fix associated errors about unused paramenters and implict sign conversions.
For sign conversion this was largely in the area of enums, so add ostream
operators for the effected enums and fix tools/generate-operator-out.py.
Tidy arena allocation code and arena allocated data types, rather than fixing
new and delete operators.
Remove dead code.

Change-Id: I5b433e722d2f75baacfacae4d32aef4a828bfe1b
diff --git a/runtime/quick_exception_handler.cc b/runtime/quick_exception_handler.cc
index c58735a..90c9fe7 100644
--- a/runtime/quick_exception_handler.cc
+++ b/runtime/quick_exception_handler.cc
@@ -297,7 +297,7 @@
 // Unwinds all instrumentation stack frame prior to catch handler or upcall.
 class InstrumentationStackVisitor : public StackVisitor {
  public:
-  InstrumentationStackVisitor(Thread* self, bool is_deoptimization, size_t frame_depth)
+  InstrumentationStackVisitor(Thread* self, size_t frame_depth)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
       : StackVisitor(self, nullptr),
         frame_depth_(frame_depth),
@@ -332,7 +332,7 @@
 
 void QuickExceptionHandler::UpdateInstrumentationStack() {
   if (method_tracing_active_) {
-    InstrumentationStackVisitor visitor(self_, is_deoptimization_, handler_frame_depth_);
+    InstrumentationStackVisitor visitor(self_, handler_frame_depth_);
     visitor.WalkStack(true);
 
     size_t instrumentation_frames_to_pop = visitor.GetInstrumentationFramesToPop();