Fix logGamma unittest to fix rounding issue on DragonFly

Author: dkgroot

std/internal/math/gammafunction.d

@@ -537,9 +537,12 @@ unittest {
             assert( feqrel(log(fabs(gamma(testpoints[i]))), testpoints[i+1]) > real.mant_dig-5);
         }
     }
-    version(DragonFlyBSD) {} else {  // FIXME
-       assert(logGamma(-50.2) == log(fabs(gamma(-50.2))));
-       assert(logGamma(-0.008) == log(fabs(gamma(-0.008))));
+    version (DragonFlyBSD) { // FIXME: DragonFlyBSD: rounding differences between logGamma() and log() (ie:llvm_log())
+        assert(feqrel(logGamma(-50.2),log(fabs(gamma(-50.2)))) > real.mant_dig-2);
+        assert(feqrel(logGamma(-0.008),log(fabs(gamma(-0.008)))) > real.mant_dig-2);
+    } else {
+        assert(logGamma(-50.2) == log(fabs(gamma(-50.2))));
+        assert(logGamma(-0.008) == log(fabs(gamma(-0.008))));
     }
     assert(feqrel(logGamma(-38.8),log(fabs(gamma(-38.8)))) > real.mant_dig-4);
     static if (real.mant_dig >= 64) // incl. 80-bit reals