- fabsl.c should be named s_fabsl.c for consistency with libmsun's

documented naming scheme (unfortunately the documentation isn't in the
   tree as far as I can tell); no repocopy is required as there is no
   history to preserve.

 - replace simple and almost-correct implementation with slightly hackish
   but definitely correct implementation (tested on i386, alpha, sparc64)
   which requires pulling in fpmath.h and the MD _fpmath.h from libc.

 - try not to make a mess of the Makefile in the process.

 - enterprising minds are encouraged to implement more C99 long double
   functions.

lib/msun/Makefile

@@ -97,11 +97,16 @@ COMMON_SRCS= b_exp.c b_log.c b_tgamma.c \
 	w_sinh.c w_sinhf.c w_sqrt.c w_sqrtf.c \
 	w_y0.c w_y0f.c w_y1.c w_y1f.c w_yn.c w_ynf.c
 
+# Location of fpmath.h and _fpmath.h
+LIBCDIR=	${.CURDIR}/../libc
+CFLAGS+=	-I${LIBCDIR}/include -I${LIBCDIR}/${MACHINE_ARCH}
+
+# C99 long double functions
+COMMON_SRCS+=	s_fabsl.c
+
 # FreeBSD's C library supplies these functions:
 #COMMON_SRCS+=	s_fabs.c s_frexp.c s_isnan.c s_ldexp.c s_modf.c
 
-COMMON_SRCS+= fabsl.c
-
 # Exclude the generic versions of what we provide in the MD area.
 .if defined(ARCH_SRCS)
 .PATH:	${.CURDIR}/${ARCH}

lib/msun/src/s_fabsl.c

@@ -30,8 +30,11 @@
 
 #include <math.h>
 
+#include "fpmath.h"
+
 long double
 fabsl(long double x)
 {
-	return (x < 0) ? -x : x;
+	((union IEEEl2bits *)&x)->bits.sign = 0;
+	return (x);
 }