Make jemalloc the default choice.

Change-Id: I5ff0cf0c396b7ae6278e6fcd5a0d50f8b966fb54
diff --git a/CleanSpec.mk b/CleanSpec.mk
index b84e1b6..841ad16 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -44,6 +44,10 @@
 #$(call add-clean-step, find $(OUT_DIR) -type f -name "IGTalkSession*" -print0 | xargs -0 rm -f)
 #$(call add-clean-step, rm -rf $(PRODUCT_OUT)/data/*)
 
+# Switching to jemalloc requires deleting these files.
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/STATIC_LIBRARIES/libc_*)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/SHARED_LIBRARIES/libc_*)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************