Assembly coded android_memset16 and android_memset32

Change-Id: Ife2dd406e1dcb962e5e97788c515ac96f5c52e44
diff --git a/libcutils/memory.c b/libcutils/memory.c
index ef6c7e6..6486b45 100644
--- a/libcutils/memory.c
+++ b/libcutils/memory.c
@@ -16,6 +16,7 @@
 
 #include <cutils/memory.h>
 
+#if !HAVE_MEMSET16
 void android_memset16(uint16_t* dst, uint16_t value, size_t size)
 {
     size >>= 1;
@@ -23,7 +24,9 @@
         *dst++ = value;
     }
 }
+#endif
 
+#if !HAVE_MEMSET32
 void android_memset32(uint32_t* dst, uint32_t value, size_t size)
 {
     size >>= 2;
@@ -31,6 +34,7 @@
         *dst++ = value;
     }
 }
+#endif
 
 #if !HAVE_STRLCPY
 /*