Add android_dlwarning() method

This is temporary method intended to use
for a toast message on preview and beta
releases. Will be removed before the
production release.

Bug: http://b/27365747
Change-Id: I39cc716bb82863ae761b6821bcec77cce6db3781
diff --git a/linker/Android.mk b/linker/Android.mk
index 85ac0ca..1620888 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -10,6 +10,7 @@
     linker.cpp \
     linker_allocator.cpp \
     linker_block_allocator.cpp \
+    linker_dlwarning.cpp \
     linker_libc_support.c \
     linker_mapped_file_fragment.cpp \
     linker_memory.cpp \