Use unified syntax to compile with both llvm and gcc.

All arch-arm and arch-arm64 .S files were compiled
by gcc with and without this patch. The output object files
were identical. When compiled with llvm and this patch,
the output files were also identical to gcc's output.

BUG: 18061004
Change-Id: I458914d512ddf5496e4eb3d288bf032cd526d32b
diff --git a/libc/arch-arm64/generic/bionic/memchr.S b/libc/arch-arm64/generic/bionic/memchr.S
index e5ea57d..a00dd8d 100644
--- a/libc/arch-arm64/generic/bionic/memchr.S
+++ b/libc/arch-arm64/generic/bionic/memchr.S
@@ -101,7 +101,7 @@
 	and	vhas_chr2.16b, vhas_chr2.16b, vrepmask.16b
 	addp	vend.16b, vhas_chr1.16b, vhas_chr2.16b		/* 256->128 */
 	addp	vend.16b, vend.16b, vend.16b			/* 128->64 */
-	mov	synd, vend.2d[0]
+	mov	synd, vend.d[0]
 	/* Clear the soff*2 lower bits */
 	lsl	tmp, soff, #1
 	lsr	synd, synd, tmp
@@ -121,7 +121,7 @@
 	/* Use a fast check for the termination condition */
 	orr	vend.16b, vhas_chr1.16b, vhas_chr2.16b
 	addp	vend.2d, vend.2d, vend.2d
-	mov	synd, vend.2d[0]
+	mov	synd, vend.d[0]
 	/* We're not out of data, loop if we haven't found the character */
 	cbz	synd, .Lloop
 
@@ -131,7 +131,7 @@
 	and	vhas_chr2.16b, vhas_chr2.16b, vrepmask.16b
 	addp	vend.16b, vhas_chr1.16b, vhas_chr2.16b		/* 256->128 */
 	addp	vend.16b, vend.16b, vend.16b			/* 128->64 */
-	mov	synd, vend.2d[0]
+	mov	synd, vend.d[0]
 	/* Only do the clear for the last possible block */
 	b.hi	.Ltail