Compiler: replace DOM traversal computation

Originally the old trace JIT used a few recursive graph walking
algorithms - which was perfectly reasonable given that the graph
size was capped at a few dozen nodes at most.  These were replaced
with iterative walk order computations  - or at least I thought
they all were.  Missed one of them, which caused a stack overflow
on a pathologically large method compilation.

Renaming of some arena_allocator items for consistency and clarity.
More detailed memory usage logging.  Reworked the allocator to waste
less space when an allocation doesn't fit and a new block must be
allocated.

Change-Id: I4d84dded3c47819eefa0de90ebb821dd12eb8be8
diff --git a/src/compiler/dex/mir_graph.h b/src/compiler/dex/mir_graph.h
index fd81967..882a508 100644
--- a/src/compiler/dex/mir_graph.h
+++ b/src/compiler/dex/mir_graph.h
@@ -592,7 +592,7 @@
    void DataFlowSSAFormat35C(MIR* mir);
    void DataFlowSSAFormat3RC(MIR* mir);
    bool FindLocalLiveIn(BasicBlock* bb);
-   bool ClearVisitedFlag(struct BasicBlock* bb);
+   void ClearAllVisitedFlags();
    bool CountUses(struct BasicBlock* bb);
    bool InferTypeAndSize(BasicBlock* bb);
    bool VerifyPredInfo(BasicBlock* bb);
@@ -621,7 +621,7 @@
    bool ComputeBlockLiveIns(BasicBlock* bb);
    bool InsertPhiNodeOperands(BasicBlock* bb);
    bool ComputeDominanceFrontier(BasicBlock* bb);
-   bool DoConstantPropogation(BasicBlock* bb);
+   void DoConstantPropogation(BasicBlock* bb);
    void CountChecks(BasicBlock* bb);
    bool CombineBlocks(BasicBlock* bb);