Get rid of OS(SOLARIS) and OS(HURD).

Source/wtf/MathExtras.h

Index: Source/wtf/MathExtras.h
diff --git a/Source/wtf/MathExtras.h b/Source/wtf/MathExtras.h
index 789632666bb4ca9a32c980702a68e6cd45d9e6a9..92237ec0e2df1208988a3e8db0d369e56fe61b1b 100644
--- a/Source/wtf/MathExtras.h
+++ b/Source/wtf/MathExtras.h
@@ -35,10 +35,6 @@
 #include <stdint.h>
 #include <stdlib.h>
 
-#if OS(SOLARIS)
-#include <ieeefp.h>
-#endif
-
 #if OS(OPENBSD)
 #include <sys/types.h>
 #include <machine/ieee.h>
@@ -77,24 +73,6 @@ inline double wtf_ceil(double x) { return copysign(ceil(x), x); }
 
 #endif
 
-#if OS(SOLARIS)
-
-namespace std {
-
-#ifndef isfinite
-inline bool isfinite(double x) { return finite(x) && !isnand(x); }
-#endif
-#ifndef signbit
-inline bool signbit(double x) { return copysign(1.0, x) < 0; }
-#endif
-#ifndef isinf
-inline bool isinf(double x) { return !finite(x) && !isnand(x); }
-#endif
-
-} // namespace std
-
-#endif
-
 #if OS(OPENBSD)
 
 namespace std {