Revert^2 "Hash-based DexCache field array."

Test: testrunner.py --host --interpreter
Bug: 30627598

This reverts commit 6374c58f2ea403b3a05fb27376110fe4d0fc8e3f.

Change-Id: I275508e288a85d3aa08f7405a1a4f362af43b775
diff --git a/runtime/linear_alloc.cc b/runtime/linear_alloc.cc
index f91b0ed..e9db9b8 100644
--- a/runtime/linear_alloc.cc
+++ b/runtime/linear_alloc.cc
@@ -33,6 +33,11 @@
   return allocator_.Alloc(size);
 }
 
+void* LinearAlloc::AllocAlign16(Thread* self, size_t size) {
+  MutexLock mu(self, lock_);
+  return allocator_.AllocAlign16(size);
+}
+
 size_t LinearAlloc::GetUsedMemory() const {
   MutexLock mu(Thread::Current(), lock_);
   return allocator_.BytesUsed();