libc: remove bcopy from memmove on 64-bit architectures

* bcopy is deprecated on LP64 by the following commit:

  ce9ce28e5d

Change-Id: I6849916f0ec4a2d0db9a360999ad1dc8edda952b

libc/arch-arm64/generic/bionic/memmove.S

@@ -35,10 +35,6 @@
 #include <private/bionic_asm.h>
 
 /* Parameters and result.  */
-#ifdef BCOPY
-#define origdstin	x1
-#define origsrc	x0
-#endif
 #define dstin	x0
 #define src	x1
 #define count	x2
@@ -59,13 +55,7 @@
 #define D_l	x13
 #define D_h	x14
 
-#ifdef BCOPY
-ENTRY(bcopy)
-	/* Swap src and dst so that a branch to memcpy doesn't cause issues. */
-	mov	tmp1, origsrc
-	mov	origsrc, origdstin
-	mov	origdstin, tmp1
-#elif defined(WMEMMOVE)
+#if defined(WMEMMOVE)
 ENTRY(wmemmove)
 	lsl	count, count, #2
 #else
@@ -332,9 +322,7 @@ ENTRY(memmove)
 	tst	count, #0x3f
 	b.ne	.Ltail63down
 	ret
-#ifdef BCOPY
-END(bcopy)
-#elif defined(WMEMMOVE)
+#if defined(WMEMMOVE)
 END(wmemmove)
 #else
 END(memmove)

libc/arch-x86_64/string/sse2-memmove-slm.S

@@ -91,9 +91,6 @@ name:		\
 	.section .text.sse2,"ax",@progbits
 ENTRY (MEMMOVE)
 	ENTRANCE
-#ifdef USE_AS_BCOPY
-	xchg	%rsi, %rdi
-#endif
 	mov	%rdi, %rax
 
 /* Check whether we should copy backward or forward.  */