Made 'wrapped call' code build with VS 2015.

src/cc65/pragma.c

@@ -525,7 +525,7 @@ static void WrappedCallPragma (StrBuf* B)
     /* Check if the name is valid */
     if (Entry && Entry->Flags & SC_FUNC) {
 
-        PushWrappedCall(Entry, Val);
+        PushWrappedCall(Entry, (unsigned char) Val);
         Entry->Flags |= SC_REF;
         Entry->V.F.Func->Flags |= FD_CALL_WRAPPER;
 

src/cc65/wrappedcall.c

@@ -97,6 +97,6 @@ void GetWrappedCall (void **Ptr, unsigned char *Val)
     } else {
         long Temp;
         IPS_Get (&WrappedCalls, &Temp, Ptr);
-        *Val = Temp;
+        *Val = (unsigned char) Temp;
     }
 }