patch 8.1.0237: Ruby on Cygwin doesn't always work

Problem:    Ruby on Cygwin doesn't always work.
Solution:   Use LIBRUBY_SO if LIBRUBY_ALIASES isn't set. (Ken Takata)

Author: brammool

src/auto/configure

@@ -7606,6 +7606,9 @@ $as_echo "$rubyhdrdir" >&6; }
 
 	if test "$enable_rubyinterp" = "dynamic"; then
 	  libruby_soname=`$vi_cv_path_ruby -r rbconfig -e "puts $ruby_rbconfig::CONFIG['LIBRUBY_ALIASES'].split[0]"`
+	  if test -z "$libruby_soname"; then
+	    libruby_soname=`$vi_cv_path_ruby -r rbconfig -e "puts $ruby_rbconfig::CONFIG['LIBRUBY_SO']"`
+	  fi
 	  $as_echo "#define DYNAMIC_RUBY 1" >>confdefs.h
 
 	  RUBY_CFLAGS="-DDYNAMIC_RUBY_DLL=\\\"$libruby_soname\\\" -DDYNAMIC_RUBY_VER=$rubyversion $RUBY_CFLAGS"

src/configure.ac

@@ -1956,6 +1956,9 @@ if test "$enable_rubyinterp" = "yes" -o "$enable_rubyinterp" = "dynamic"; then
 	AC_DEFINE(FEAT_RUBY)
 	if test "$enable_rubyinterp" = "dynamic"; then
 	  libruby_soname=`$vi_cv_path_ruby -r rbconfig -e "puts $ruby_rbconfig::CONFIG[['LIBRUBY_ALIASES']].split[[0]]"`
+	  if test -z "$libruby_soname"; then
+	    libruby_soname=`$vi_cv_path_ruby -r rbconfig -e "puts $ruby_rbconfig::CONFIG[['LIBRUBY_SO']]"`
+	  fi
 	  AC_DEFINE(DYNAMIC_RUBY)
 	  RUBY_CFLAGS="-DDYNAMIC_RUBY_DLL=\\\"$libruby_soname\\\" -DDYNAMIC_RUBY_VER=$rubyversion $RUBY_CFLAGS"
 	  RUBY_LIBS=

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    237,
 /**/
     236,
 /**/