Fix lgamma_r/lgammaf_r/lgammal_r for -0.

Upstream has implemented lgammal/lgammal_r for ld128, and fixed the
sign problem we reported with all the lgamma*_r functions and -0.

Bug: 17471883
Change-Id: Ibb175d9cab67efae75f1010796fd44c9ba6ce4fc
diff --git a/libm/include/math.h b/libm/include/math.h
index 1fcc578..1542374 100644
--- a/libm/include/math.h
+++ b/libm/include/math.h
@@ -459,9 +459,12 @@
 long double	tanl(long double);
 long double	tgammal(long double);
 long double	truncl(long double);
-
 #endif /* __ISO_C_VISIBLE >= 1999 */
 
+#if __BSD_VISIBLE
+long double	lgammal_r(long double, int *);
+#endif
+
 #if defined(__USE_GNU)
 void sincos(double, double*, double*);
 void sincosf(float, float*, float*);