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/dex/quick/gen_common.cc b/compiler/dex/quick/gen_common.cc
index 215257b..9410f7e 100644
--- a/compiler/dex/quick/gen_common.cc
+++ b/compiler/dex/quick/gen_common.cc
@@ -212,8 +212,7 @@
 }
 
 void Mir2Lir::GenCompareAndBranch(Instruction::Code opcode, RegLocation rl_src1,
-                                  RegLocation rl_src2, LIR* taken,
-                                  LIR* fall_through) {
+                                  RegLocation rl_src2, LIR* taken) {
   ConditionCode cond;
   RegisterClass reg_class = (rl_src1.ref || rl_src2.ref) ? kRefReg : kCoreReg;
   switch (opcode) {
@@ -276,8 +275,7 @@
   OpCmpBranch(cond, rl_src1.reg, rl_src2.reg, taken);
 }
 
-void Mir2Lir::GenCompareZeroAndBranch(Instruction::Code opcode, RegLocation rl_src, LIR* taken,
-                                      LIR* fall_through) {
+void Mir2Lir::GenCompareZeroAndBranch(Instruction::Code opcode, RegLocation rl_src, LIR* taken) {
   ConditionCode cond;
   RegisterClass reg_class = rl_src.ref ? kRefReg : kCoreReg;
   rl_src = LoadValue(rl_src, reg_class);
@@ -2134,12 +2132,14 @@
 
 /* Call out to helper assembly routine that will null check obj and then lock it. */
 void Mir2Lir::GenMonitorEnter(int opt_flags, RegLocation rl_src) {
+  UNUSED(opt_flags);  // TODO: avoid null check with specialized non-null helper.
   FlushAllRegs();
   CallRuntimeHelperRegLocation(kQuickLockObject, rl_src, true);
 }
 
 /* Call out to helper assembly routine that will null check obj and then unlock it. */
 void Mir2Lir::GenMonitorExit(int opt_flags, RegLocation rl_src) {
+  UNUSED(opt_flags);  // TODO: avoid null check with specialized non-null helper.
   FlushAllRegs();
   CallRuntimeHelperRegLocation(kQuickUnlockObject, rl_src, true);
 }