Add GNU extensions mempcpy and wmemcpy.

Used by elfutils. On the bright side, they stopped using __mempcpy.

Bug: 18374026
Change-Id: Id29bbe6ef1c5ed5a171bb6c32182f129d8332abb
diff --git a/libc/Android.mk b/libc/Android.mk
index 7dc7cbf..9dd3864 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -143,6 +143,7 @@
     bionic/mbrtoc16.cpp \
     bionic/mbrtoc32.cpp \
     bionic/mbstate.cpp \
+    bionic/mempcpy.cpp \
     bionic/mkdir.cpp \
     bionic/mkfifo.cpp \
     bionic/mknod.cpp \
@@ -214,6 +215,7 @@
     bionic/wait.cpp \
     bionic/wchar.cpp \
     bionic/wctype.cpp \
+    bionic/wmempcpy.cpp \
 
 libc_bionic_src_files :=