Move arenas into runtime

Moved arena pool into the runtime.

Motivation:
Allow GC to use arena allocators, recycle arena pool for linear alloc.

Bug: 19264997
Change-Id: I8ddbb6d55ee923a980b28fb656c758c5d7697c2f
diff --git a/runtime/Android.mk b/runtime/Android.mk
index 4714610..c647cc2 100644
--- a/runtime/Android.mk
+++ b/runtime/Android.mk
@@ -22,10 +22,12 @@
   atomic.cc.arm \
   barrier.cc \
   base/allocator.cc \
+  base/arena_allocator.cc \
   base/bit_vector.cc \
   base/hex_dump.cc \
   base/logging.cc \
   base/mutex.cc \
+  base/scoped_arena_allocator.cc \
   base/scoped_flock.cc \
   base/stringpiece.cc \
   base/stringprintf.cc \