Add back method needed by CoreRT

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>

diff --git a/src/mscorlib/shared/System/Number.Parsing.cs b/src/mscorlib/shared/System/Number.Parsing.cs
index 70fc9ae..c6ae34d 100644 (file)
--- a/src/mscorlib/shared/System/Number.Parsing.cs
+++ b/src/mscorlib/shared/System/Number.Parsing.cs
@@ -956,6 +956,9 @@ namespace System
 
             public static unsafe ulong Mantissa(double d) =>
                 *((ulong*)&d) & 0x000fffffffffffff;
+
+            public static unsafe bool Sign(double d) =>
+                (*((uint*)&d + 1) >> 31) != 0;
         }
     }
 }