remove the last of possible-textrels from i386 asm

none of these are actual textrels because of ld-time binding performed
by -Bsymbolic-functions, but I'm changing them with the goal of making
ld-time binding purely an optimization rather than relying on it for
semantic purposes.

in the case of memmove's call to memcpy, making it explicit that the
memmove asm is assuming the forward-copying behavior of the memcpy asm
is desirable anyway; in case memcpy is ever changed, the semantic
mismatch would be apparent while editing memmcpy.s.

src/string/i386/memcpy.s

@@ -1,6 +1,9 @@
 .global memcpy
+.global __memcpy_fwd
+.hidden __memcpy_fwd
 .type memcpy,@function
 memcpy:
+__memcpy_fwd:
 	push %esi
 	push %edi
 	mov 12(%esp),%edi

src/string/i386/memmove.s

@@ -4,7 +4,8 @@ memmove:
 	mov 4(%esp),%eax
 	sub 8(%esp),%eax
 	cmp 12(%esp),%eax
-	jae memcpy
+.hidden __memcpy_fwd
+	jae __memcpy_fwd
 	push %esi
 	push %edi
 	mov 12(%esp),%edi