patch 8.1.0987: unnecessary condition in #ifdef

Problem:    Unnecessary condition in #ifdef.
Solution:   Remove using CYGWIN32. (Ken Takata)
diff --git a/src/os_unix.h b/src/os_unix.h
index 8919ff0..5df943c 100644
--- a/src/os_unix.h
+++ b/src/os_unix.h
@@ -33,7 +33,7 @@
 # include <stdlib.h>
 #endif
 
-#if defined(__CYGWIN__) || defined(__CYGWIN32__)
+#ifdef __CYGWIN__
 # define WIN32UNIX	/* Compiling for Win32 using Unix files. */
 # define BINARY_FILE_IO
 
diff --git a/src/version.c b/src/version.c
index 3132a1d..e7d4923 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    987,
+/**/
     986,
 /**/
     985,
diff --git a/src/xxd/xxd.c b/src/xxd/xxd.c
index c24089e..b9f6041 100644
--- a/src/xxd/xxd.c
+++ b/src/xxd/xxd.c
@@ -71,7 +71,7 @@
 # define _CRT_SECURE_NO_DEPRECATE
 # define _CRT_NONSTDC_NO_DEPRECATE
 #endif
-#if !defined(CYGWIN) && (defined(CYGWIN32) || defined(__CYGWIN__) || defined(__CYGWIN32__))
+#if !defined(CYGWIN) && defined(__CYGWIN__)
 # define CYGWIN
 #endif