ARM64: Enable Optimizing compiler image generation.

Enable Optimizing Compiler image generation for ARM64.

Change-Id: If28426920f8887a3f78cb8c69bc8c1293131b85d
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
diff --git a/build/Android.oat.mk b/build/Android.oat.mk
index 9dbd2f4..d4fd519 100644
--- a/build/Android.oat.mk
+++ b/build/Android.oat.mk
@@ -161,20 +161,11 @@
   # a dex2oat change to catch regressions early.
   ifeq ($(ART_USE_OPTIMIZING_COMPILER), true)
     core_dex2oat_dependency := $(DEX2OAT)
-    ifeq ($($(3)TARGET_ARCH),arm64)
-      # TODO: Enable image generation on arm64 once the backend
-      # is on par with other architectures.
-      core_compile_options += --compiler-filter=interpret-only
-    endif
   endif
 
   ifeq ($(1),optimizing)
-    ifeq ($($(3)TARGET_ARCH),arm64)
-      core_compile_options += --compiler-filter=interpret-only
-    else
-      core_compile_options += --compiler-backend=Optimizing
-      core_dex2oat_dependency := $(DEX2OAT)
-    endif
+    core_compile_options += --compiler-backend=Optimizing
+    core_dex2oat_dependency := $(DEX2OAT)
     core_infix := -optimizing
   endif
   ifeq ($(1),interpreter)