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/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index d41d5a0..ac328c3 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -645,6 +645,7 @@
 }
 
 void InstructionCodeGeneratorX86::VisitExit(HExit* exit) {
+  UNUSED(exit);
   if (kIsDebugBuild) {
     __ Comment("Unreachable");
     __ int3();
@@ -734,6 +735,7 @@
 
 void InstructionCodeGeneratorX86::VisitLoadLocal(HLoadLocal* load) {
   // Nothing to do, this is driven by the code generator.
+  UNUSED(load);
 }
 
 void LocationsBuilderX86::VisitStoreLocal(HStoreLocal* store) {
@@ -762,6 +764,7 @@
 }
 
 void InstructionCodeGeneratorX86::VisitStoreLocal(HStoreLocal* store) {
+  UNUSED(store);
 }
 
 void LocationsBuilderX86::VisitCondition(HCondition* comp) {
@@ -851,6 +854,7 @@
 
 void InstructionCodeGeneratorX86::VisitIntConstant(HIntConstant* constant) {
   // Will be generated at use site.
+  UNUSED(constant);
 }
 
 void LocationsBuilderX86::VisitLongConstant(HLongConstant* constant) {
@@ -861,6 +865,7 @@
 
 void InstructionCodeGeneratorX86::VisitLongConstant(HLongConstant* constant) {
   // Will be generated at use site.
+  UNUSED(constant);
 }
 
 void LocationsBuilderX86::VisitFloatConstant(HFloatConstant* constant) {
@@ -871,6 +876,7 @@
 
 void InstructionCodeGeneratorX86::VisitFloatConstant(HFloatConstant* constant) {
   // Will be generated at use site.
+  UNUSED(constant);
 }
 
 void LocationsBuilderX86::VisitDoubleConstant(HDoubleConstant* constant) {
@@ -881,6 +887,7 @@
 
 void InstructionCodeGeneratorX86::VisitDoubleConstant(HDoubleConstant* constant) {
   // Will be generated at use site.
+  UNUSED(constant);
 }
 
 void LocationsBuilderX86::VisitReturnVoid(HReturnVoid* ret) {
@@ -888,6 +895,7 @@
 }
 
 void InstructionCodeGeneratorX86::VisitReturnVoid(HReturnVoid* ret) {
+  UNUSED(ret);
   codegen_->GenerateFrameExit();
   __ ret();
 }
@@ -1456,6 +1464,7 @@
 }
 
 void InstructionCodeGeneratorX86::VisitParameterValue(HParameterValue* instruction) {
+  UNUSED(instruction);
 }
 
 void LocationsBuilderX86::VisitNot(HNot* not_) {
@@ -1550,6 +1559,7 @@
 }
 
 void InstructionCodeGeneratorX86::VisitPhi(HPhi* instruction) {
+  UNUSED(instruction);
   LOG(FATAL) << "Unreachable";
 }
 
@@ -2026,9 +2036,11 @@
 
 void InstructionCodeGeneratorX86::VisitTemporary(HTemporary* temp) {
   // Nothing to do, this is driven by the code generator.
+  UNUSED(temp);
 }
 
 void LocationsBuilderX86::VisitParallelMove(HParallelMove* instruction) {
+  UNUSED(instruction);
   LOG(FATAL) << "Unreachable";
 }