patch 8.1.0983: checking __CYGWIN32__ unnecessarily

Problem:    Checking __CYGWIN32__ unnecessarily.
Solution:   Remove the checks. (Ken Takata)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 7f50555..0ad8d84 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -6155,7 +6155,7 @@
 #ifdef MSWIN
 	"win32",
 #endif
-#if defined(UNIX) && (defined(__CYGWIN32__) || defined(__CYGWIN__))
+#if defined(UNIX) && defined(__CYGWIN__)
 	"win32unix",
 #endif
 #ifdef _WIN64
diff --git a/src/os_unix.c b/src/os_unix.c
index 001f085..3471810 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1605,7 +1605,7 @@
 {
     /* This function should not return, it causes exit().  Longjump instead. */
     LONGJMP(lc_jump_env, 1);
-#  if defined(VMS) || defined(__CYGWIN__) || defined(__CYGWIN32__)
+#  if defined(VMS) || defined(__CYGWIN__)
     return 0;  /* avoid the compiler complains about missing return value */
 #  endif
 }
@@ -1627,7 +1627,7 @@
 
     /* This function should not return, it causes exit().  Longjump instead. */
     LONGJMP(x_jump_env, 1);
-# if defined(VMS) || defined(__CYGWIN__) || defined(__CYGWIN32__)
+# if defined(VMS) || defined(__CYGWIN__)
     return 0;  /* avoid the compiler complains about missing return value */
 # endif
 }
@@ -6713,7 +6713,7 @@
     }
     vim_free(tempname);
 
-# if defined(__CYGWIN__) || defined(__CYGWIN32__)
+# ifdef __CYGWIN__
     /* Translate <CR><NL> into <NL>.  Caution, buffer may contain NUL. */
     p = buffer;
     for (i = 0; i < (int)len; ++i)
diff --git a/src/os_win32.c b/src/os_win32.c
index b923315..4ac5ebd 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -2094,8 +2094,8 @@
     return TRUE;
 }
 
-#if ((defined(__MINGW32__) || defined (__CYGWIN32__)) && \
-       __MSVCRT_VERSION__ >= 0x800) || (defined(_MSC_VER) && _MSC_VER >= 1400)
+#if (defined(__MINGW32__) && __MSVCRT_VERSION__ >= 0x800) || \
+	(defined(_MSC_VER) && _MSC_VER >= 1400)
 /*
  * Bad parameter handler.
  *
diff --git a/src/version.c b/src/version.c
index 8e9c87a..e2e82f5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -780,6 +780,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    983,
+/**/
     982,
 /**/
     981,