Build: Support for compiled-classes file

Allow a compiled-classes file for pre-opting.

Bug: 18410571
Change-Id: I8c69dd0fb8c04aaae0c4f062049cc9cce7d755c7
diff --git a/core/dex_preopt_libart.mk b/core/dex_preopt_libart.mk
index 811062a..cfbf221 100644
--- a/core/dex_preopt_libart.mk
+++ b/core/dex_preopt_libart.mk
@@ -20,6 +20,10 @@
 PRELOADED_CLASSES := $(call word-colon,1,$(firstword \
     $(filter %system/etc/preloaded-classes,$(PRODUCT_COPY_FILES))))
 
+# Use the first compiled-classes file in PRODUCT_COPY_FILES.
+COMPILED_CLASSES := $(call word-colon,1,$(firstword \
+    $(filter %system/etc/compiled-classes,$(PRODUCT_COPY_FILES))))
+
 # start of image reserved address space
 LIBART_IMG_HOST_BASE_ADDRESS   := 0x60000000
 LIBART_IMG_TARGET_BASE_ADDRESS := 0x70000000