The constant has been deleted from libc.h and lib.h.
A comment has been added to tas.s (kernel and libc)
to remind that the constant is the same.

Reference: /n/patches.lsub.org/patch/deaddead
Date: Tue Jun 26 11:10:13 CES 2012
Signed-off-by: esoriano@lsub.org

--- /sys/src/libc/386/tas.s	Thu Apr 12 12:26:15 2012
+++ /sys/src/libc/386/tas.s	Tue Jun 26 10:40:33 2012
@@ -1,6 +1,9 @@
+/*
+ * The kernel and the libc use the same constant for TAS
+ */
 TEXT	_tas(SB),$0
 
-	MOVL	$0xdeadead,AX
+	MOVL	$0xdeaddead,AX
 	MOVL	l+0(FP),BX
 	XCHGL	AX,(BX)
 	RET
--- /sys/src/libc/amd64/tas.s	Thu Apr 12 12:26:17 2012
+++ /sys/src/libc/amd64/tas.s	Tue Jun 26 10:40:31 2012
@@ -1,5 +1,8 @@
+/*
+ * The kernel and the libc use the same constant for TAS
+ */
 TEXT	_tas(SB),$0
 
-	MOVL	$0xdeadead,AX
+	MOVL	$0xdeaddead,AX
 	XCHGL	AX,(RARG)
 	RET