remove _xinc and _xdec from the c library, as the standard functions
are now ainc and adec (see atom(2)).

aside:
i am not sure about the difference between the rb kernel's implementation
of _xdec.  it includes a SYNC, which i don't understand.  any body have
background on this?

Reference: /n/atom/patch/applied/noclibxinc
Date: Fri Jun  6 17:44:24 CES 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/libc/power/atom.s	Fri Jun  6 17:42:35 2014
+++ /sys/src/libc/power/atom.s	Fri Jun  6 17:42:35 2014
@@ -1,21 +1,21 @@
 TEXT	ainc(SB),$0	/* int ainc(int *); */
 	MOVW	R3, R4
-xincloop:
+aincloop:
 	LWAR	(R4), R3
 	ADD	$1, R3
 	DCBT	(R4)				/* fix 405 errata cpu_210 */
 	STWCCC	R3, (R4)
-	BNE	xincloop
+	BNE	aincloop
 	RETURN
 
 TEXT	adec(SB),$0	/* int adec(int *); */
 	MOVW	R3, R4
-xdecloop:
+adecloop:
 	LWAR	(R4), R3
 	ADD	$-1, R3
 	DCBT	(R4)				/* fix 405 errata cpu_210 */
 	STWCCC	R3, (R4)
-	BNE	xdecloop
+	BNE	adecloop
 	RETURN
 
 TEXT	loadlink(SB), $0
--- /sys/src/libc/mips/atom.s	Fri Jun  6 17:42:37 2014
+++ /sys/src/libc/mips/atom.s	Fri Jun  6 17:42:38 2014
@@ -6,8 +6,7 @@
 #define	SC(base, rt)	WORD	$((070<<26)|((base)<<21)|((rt)<<16))
 #define	NOOP		WORD	$0x27
 
-TEXT ainc(SB), 1, $-4			/* int ainc(long *); */
-TEXT _xinc(SB), 1, $-4			/* void _xinc(long *); */
+TEXT ainc(SB), 1, $-4			/* int ainc(int *); */
 	MOVW	R1, R2			/* address of counter */
 loop:	MOVW	$1, R3
 	LL(2, 1)
@@ -19,8 +18,7 @@
 	BEQ	R3,loop
 	RET
 
-TEXT adec(SB), 1, $-4			/* int adec(long*); */
-TEXT _xdec(SB), 1, $-4			/* long _xdec(long *); */
+TEXT adec(SB), 1, $-4			/* int adec(int*); */
 	MOVW	R1, R2			/* address of counter */
 loop1:	MOVW	$-1, R3
 	LL(2, 1)
--- /sys/src/libc/arm/atom.s	Fri Jun  6 17:42:39 2014
+++ /sys/src/libc/arm/atom.s	Fri Jun  6 17:42:40 2014
@@ -25,7 +25,6 @@
 	MOVW	$0, R0
 	RET
 
-TEXT _xinc(SB), $0	/* void	_xinc(long *); */
 TEXT ainc(SB), $0	/* int ainc(int *); */
 spinainc:
 	LDREX(0,3)	/*	LDREX	0(R0),R3	*/
@@ -36,7 +35,6 @@
 	MOVW	R3, R0
 	RET
 
-TEXT _xdec(SB), $0	/* long _xdec(long *); */
 TEXT adec(SB), $0	/* int adec(int *); */
 spinadec:
 	LDREX(0,3)	/*	LDREX	0(R0),R3	*/