Fix compilation problem whit the following config options:

UCLIBC_HAS_STRING_GENERIC_OPT=y
UCLIBC_HAS_STRING_ARCH_OPT is not set
by making WORD_COPY_FWD macros visible.

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

libc/string/generic/memcopy.h

@@ -107,7 +107,6 @@ typedef unsigned char byte;
 	}								      \
     } while (0)
 
-#ifdef __ARCH_HAS_BWD_MEMCPY__
 /* Copy *up to* NBYTES bytes from SRC_BP to DST_BP, with
    the assumption that DST_BP is aligned on an OPSIZ multiple.  If
    not all bytes could be easily copied, store remaining number of bytes
@@ -126,8 +125,6 @@ typedef unsigned char byte;
       (nbytes_left) = (nbytes) % OPSIZ;					      \
     } while (0)
 
-#endif
-
 /* Copy *up to* NBYTES_TO_COPY bytes from SRC_END_PTR to DST_END_PTR,
    beginning at the words (of type op_t) right before the pointers and
    continuing towards smaller addresses.  May take advantage of that

libc/string/generic/memcpy.c

@@ -22,6 +22,7 @@
 #include <string.h>
 #include "memcopy.h"
 #include "pagecopy.h"
+#include "_memcpy_fwd.c"
 
 /* Experimentally off - libc_hidden_proto(memcpy) */