Patch #551093: Let cygwin default to --enable-shared.

configure

 #! /bin/sh
-# From configure.in Revision: 1.311 .
+# From configure.in Revision: 1.313 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53.
 #
@@ -3070,7 +3070,12 @@ fi;
 
 if test -z "$enable_shared"
 then
-  enable_shared="no"
+  case $ac_sys_system in
+  CYGWIN*)
+    enable_shared="yes";;
+  *)
+    enable_shared="no";;
+  esac
 fi
 echo "$as_me:$LINENO: result: $enable_shared" >&5
 echo "${ECHO_T}$enable_shared" >&6

configure.in

@@ -337,7 +337,12 @@ AC_ARG_ENABLE(shared,
 
 if test -z "$enable_shared"
 then 
-  enable_shared="no"
+  case $ac_sys_system in
+  CYGWIN*)
+    enable_shared="yes";;
+  *)
+    enable_shared="no";;
+  esac
 fi
 AC_MSG_RESULT($enable_shared)