Unify our assembler macros.

Our <machine/asm.h> files were modified from upstream, to the extent
that no architecture was actually using the upstream ENTRY or END macros,
assuming that architecture even had such a macro upstream. This patch moves
everyone to the same macros, with just a few tweaks remaining in the
<machine/asm.h> files, which no one should now use directly.

I've removed most of the unused cruft from the <machine/asm.h> files, though
there's still rather a lot in the mips/mips64 ones.

Bug: 12229603
Change-Id: I2fff287dc571ac1087abe9070362fb9420d85d6d
diff --git a/libc/arch-mips/bionic/memcmp16.S b/libc/arch-mips/bionic/memcmp16.S
index a2b2544..f9d14a9 100644
--- a/libc/arch-mips/bionic/memcmp16.S
+++ b/libc/arch-mips/bionic/memcmp16.S
@@ -25,31 +25,26 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-	.text
 
-/*
- * u4 __memcmp16(const u2* s0, const u2* s1, size_t count);
- */
-	.type	__memcmp16, @function
-	.global	__memcmp16
-	.align	4
-	.ent __memcmp16
-__memcmp16:
-	li	$t0,0
-	li	$t1,0
-	beqz	$a2,done		/* 0 length string */ 
-	beq	$a0,$a1,done		/* strings are identical */
+#include <private/bionic_asm.h>
+
+// u4 __memcmp16(const u2*, const u2*, size_t);
+ENTRY(__memcmp16)
+	li	t0,0
+	li	t1,0
+	beqz	a2,done		/* 0 length string */ 
+	beq	a0,a1,done		/* strings are identical */
 
 	/* Unoptimised... */
-1:	lhu	$t0,0($a0)
-	lhu	$t1,0($a1)
-	addu	$a1,2
-	bne	$t0,$t1,done
-	addu	$a0,2
-	subu	$a2,1
-	bnez	$a2,1b
+1:	lhu	t0,0(a0)
+	lhu	t1,0(a1)
+	addu	a1,2
+	bne	t0,t1,done
+	addu	a0,2
+	subu	a2,1
+	bnez	a2,1b
 
 done:
-	subu	$v0,$t0,$t1
-	j	$ra
-        .end __memcmp16
+	subu	v0,t0,t1
+	j	ra
+END(__memcmp16)