Optimizing: Fix register allocator validation memory usage.

Also attribute ArenaBitVector allocations to appropriate
passes. This was used to track down the source of the
excessive memory alloactions.

Bug: 27690481

Change-Id: Ib895984cb7c04e24cbc7abbd8322079bab8ab100
diff --git a/compiler/optimizing/builder.cc b/compiler/optimizing/builder.cc
index 57660c2..124afbc 100644
--- a/compiler/optimizing/builder.cc
+++ b/compiler/optimizing/builder.cc
@@ -367,7 +367,8 @@
   ArenaBitVector* native_debug_info_locations;
   if (native_debuggable) {
     const uint32_t num_instructions = code_item.insns_size_in_code_units_;
-    native_debug_info_locations = new (arena_) ArenaBitVector (arena_, num_instructions, false);
+    native_debug_info_locations =
+        ArenaBitVector::Create(arena_, num_instructions, false, kArenaAllocGraphBuilder);
     FindNativeDebugInfoLocations(code_item, native_debug_info_locations);
   }