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/mips/codegen_mips.h b/compiler/dex/quick/mips/codegen_mips.h
index 508d474..dc6930c 100644
--- a/compiler/dex/quick/mips/codegen_mips.h
+++ b/compiler/dex/quick/mips/codegen_mips.h
@@ -121,7 +121,7 @@
     void GenSelect(BasicBlock* bb, MIR* mir);
     void GenSelectConst32(RegStorage left_op, RegStorage right_op, ConditionCode code,
                           int32_t true_val, int32_t false_val, RegStorage rs_dest,
-                          int dest_reg_class) OVERRIDE;
+                          RegisterClass dest_reg_class) OVERRIDE;
     bool GenMemBarrier(MemBarrierKind barrier_kind);
     void GenMoveException(RegLocation rl_dest);
     void GenMultiplyByTwoBitMultiplier(RegLocation rl_src, RegLocation rl_result, int lit,
@@ -172,10 +172,10 @@
     bool InexpensiveConstantLong(int64_t value);
     bool InexpensiveConstantDouble(int64_t value);
 
-    bool WideGPRsAreAliases() OVERRIDE {
+    bool WideGPRsAreAliases() const OVERRIDE {
       return false;  // Wide GPRs are formed by pairing.
     }
-    bool WideFPRsAreAliases() OVERRIDE {
+    bool WideFPRsAreAliases() const OVERRIDE {
       return false;  // Wide FPRs are formed by pairing.
     }